[PATCH v2 00/35] Add RISC-V Hypervisor Extension v0.5

[PATCH v2 00/35] Add RISC-V Hypervisor Extension v0.5

[Alistair Francis]

This patch series adds the RISC-V Hypervisor extension v0.5. This is the
latest draft spec of the Hypervisor extension.

The Hypervisor extension is disabled by default, so this series should
result in no changes to anyone using QEMU unless they enable the
extension. The extention can be enabled with the -cpu property (see
below).

Testing of this implementation has been done by using the baremetal
Xvisor Hypervisor. We are able to run two Linux guests (that's all I
have tried) as guests in 64-bit. In 32-bit so far I can only run
baremetal guests, but I think this is a baremetal boot loader issue and
not an issue in QEMU.

The RISC-V KVM implementation was also written using these patches. The
KVM implementation is currently under review.

At the moment this spec is in a draft state and is subject to change. As
QEMU is extreamly useful in early bring up I think it makes sense for
QEMU to support non-frozen extensions.

Thanks to Anup for doing the initial port of Xvisor. The port is avaliable here:
https://github.com/avpatel/xvisor-next and will run on QEMU.

Also thanks to Atish for implementing the SBI call support in Xvisor and
for lots of help debugging.

To run this yourself:
 1. Apply this patch series to QEMU. The latest branch can be found here:
      https://github.com/alistair23/qemu/tree/mainline/alistair/riscv-hyp-ext-v0.5.next
 2. Get the version of OpenSBI that supports the H extension. This can
    be found here:
      https://github.com/avpatel/opensbi/tree/riscv_hyp_ext_0_5_v1
 3. Build the next release of Xvisor. It is available here:
      https://github.com/avpatel/xvisor-next
 4. Make sure you build the Xvisor tests, see here for details:
      https://github.com/avpatel/xvisor-next/tree/master/tests/riscv/virt64/linux
 5. Run QEMU:
     ./riscv64-softmmu/qemu-system-riscv64 -nographic \
       -machine virt -cpu rv64,x-h=true \
       -serial mon:stdio -serial null -m 4G \
       -device loader,file=vmm.bin,addr=0x80200000 \
       -kernel fw_jump.elf \
       -initrd vmm-disk-linux.img \
       -append "vmm.console=uart@10000000 vmm.bootcmd=\"vfs mount initrd /;vfs run /boot.xscript;vfs cat /system/banner.txt\""

   Once you get to the prompt you can start the geust by running:
     guest kick guest0
   You can then bind to the serial port using:
     vserial bind guest0/uart0
   Then you can start Linux using:
     autoexec

 This was all tested with the mainline 5.2/5.3 kernels.

There is very early work on a Xen port as well which is avaliable here:
https://github.com/alistair23/xen/tree/alistair/riscv-port

ToDo/Issues
 - Get 32-bit fully working

v2:
 - Don't use riscv_cpu_set_force_hs_excep() for 2nd stage MMU fauls as
   the v0.5 spec has a specific fault
 - Address review comments
 - Rebase on master
 - Remove pointers for mstatus

Alistair Francis (35):
  target/riscv: Convert MIP CSR to target_ulong
  target/riscv: Add the Hypervisor extension
  target/riscv: Add the Hypervisor CSRs to CPUState
  target/riscv: Add support for the new execption numbers
  target/riscv: Rename the H irqs to VS irqs
  target/riscv: Add the virtulisation mode
  target/riscv: Add the force HS exception mode
  target/riscv: Fix CSR perm checking for HS mode
  target/riscv: Print priv and virt in disas log
  target/riscv: Dump Hypervisor registers if enabled
  target/riscv: Add Hypervisor CSR access functions
  target/riscv: Add Hypervisor virtual CSRs accesses
  target/riscv: Add Hypervisor machine CSRs accesses
  target/riscv: Add virtual register swapping function
  target/riscv: Set VS bits in mideleg for Hyp extension
  target/riscv: Extend the MIE CSR to support virtulisation
  target/riscv: Extend the SIP CSR to support virtulisation
  target/riscv: Add support for virtual interrupt setting
  target/ricsv: Flush the TLB on virtulisation mode changes
  target/riscv: Generate illegal instruction on WFI when V=1
  target/riscv: Add hypvervisor trap support
  target/riscv: Add Hypervisor trap return support
  target/riscv: Add hfence instructions
  target/riscv: Remove the hret instruction
  target/riscv: Only set TB flags with FP status if enabled
  target/riscv: Disable guest FP support based on virtual status
  target/riscv: Mark both sstatus and msstatus_hs as dirty
  target/riscv: Respect MPRV and SPRV for floating point ops
  target/riscv: Allow specifying MMU stage
  target/riscv: Implement second stage MMU
  target/riscv: Raise the new execptions when 2nd stage translation
    fails
  target/riscv: Set htval and mtval2 on execptions
  target/riscv: Add support for the 32-bit MSTATUSH CSR
  target/riscv: Add the MSTATUS_MPV_ISSET helper macro
  target/riscv: Allow enabling the Hypervisor extension

 target/riscv/cpu.c                            |  57 ++-
 target/riscv/cpu.h                            |  58 ++-
 target/riscv/cpu_bits.h                       | 111 ++--
 target/riscv/cpu_helper.c                     | 481 ++++++++++++++++--
 target/riscv/csr.c                            | 369 +++++++++++++-
 target/riscv/gdbstub.c                        |  11 +-
 target/riscv/insn32.decode                    |  22 +-
 .../riscv/insn_trans/trans_privileged.inc.c   |  45 +-
 target/riscv/op_helper.c                      |  71 ++-
 target/riscv/translate.c                      |  34 ++
 10 files changed, 1130 insertions(+), 129 deletions(-)

-- 
2.25.0

[PATCH v2 01/35] target/riscv: Convert MIP CSR to target_ulong

[Alistair Francis]

The MIP CSR is a xlen CSR, it was only 32-bits to allow atomic access.
Now that we don't use atomics for MIP we can change this back to a xlen
CSR.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.c | 2 +-
 target/riscv/cpu.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 8c86ebc109..efbd676edb 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -224,7 +224,7 @@ static void riscv_cpu_dump_state(CPUState *cs, FILE *f, int flags)
 #ifndef CONFIG_USER_ONLY
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mhartid ", env->mhartid);
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ", env->mstatus);
-    qemu_fprintf(f, " %s 0x%x\n", "mip     ", env->mip);
+    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mip     ", env->mip);
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mie     ", env->mie);
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mideleg ", env->mideleg);
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "medeleg ", env->medeleg);
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index de0a8d893a..95de9e58a2 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -121,7 +121,7 @@ struct CPURISCVState {
     target_ulong mhartid;
     target_ulong mstatus;
 
-    uint32_t mip;
+    target_ulong mip;
     uint32_t miclaim;
 
     target_ulong mie;
-- 
2.25.0

[PATCH v2 02/35] target/riscv: Add the Hypervisor extension

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Chih-Min Chao <chihmin.chao@sifive.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
---
 target/riscv/cpu.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 95de9e58a2..010125efd6 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -67,6 +67,7 @@
 #define RVC RV('C')
 #define RVS RV('S')
 #define RVU RV('U')
+#define RVH RV('H')
 
 /* S extension denotes that Supervisor mode exists, however it is possible
    to have a core that support S mode but does not have an MMU and there
-- 
2.25.0

[PATCH v2 03/35] target/riscv: Add the Hypervisor CSRs to CPUState

[Alistair Francis]

Add the Hypervisor CSRs to CPUState and at the same time (to avoid
bisect issues) update the CSR macros for the v0.5 Hyp spec.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h      | 21 +++++++++++++++++++++
 target/riscv/cpu_bits.h | 34 +++++++++++++++++++++-------------
 target/riscv/gdbstub.c  | 11 ++++++-----
 3 files changed, 48 insertions(+), 18 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 010125efd6..c7f7ae5c38 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -143,6 +143,27 @@ struct CPURISCVState {
     target_ulong mcause;
     target_ulong mtval;  /* since: priv-1.10.0 */
 
+    /* Hypervisor CSRs */
+    target_ulong hstatus;
+    target_ulong hedeleg;
+    target_ulong hideleg;
+    target_ulong hcounteren;
+    target_ulong htval;
+    target_ulong htinst;
+    target_ulong hgatp;
+
+    /* Virtual CSRs */
+    target_ulong vsstatus;
+    target_ulong vstvec;
+    target_ulong vsscratch;
+    target_ulong vsepc;
+    target_ulong vscause;
+    target_ulong vstval;
+    target_ulong vsatp;
+
+    target_ulong mtval2;
+    target_ulong mtinst;
+
     target_ulong scounteren;
     target_ulong mcounteren;
 
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index e99834856c..25c0fb258d 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -177,8 +177,14 @@
 #define CSR_HSTATUS         0x600
 #define CSR_HEDELEG         0x602
 #define CSR_HIDELEG         0x603
-#define CSR_HCOUNTERNEN     0x606
+#define CSR_HIE             0x604
+#define CSR_HCOUNTEREN      0x606
+#define CSR_HTVAL           0x643
+#define CSR_HIP             0x644
+#define CSR_HTINST          0x64A
 #define CSR_HGATP           0x680
+#define CSR_HTIMEDELTA      0x605
+#define CSR_HTIMEDELTAH     0x615
 
 #if defined(TARGET_RISCV32)
 #define HGATP_MODE           SATP32_MODE
@@ -191,6 +197,20 @@
 #define HGATP_PPN            SATP64_PPN
 #endif
 
+/* Virtual CSRs */
+#define CSR_VSSTATUS        0x200
+#define CSR_VSIE            0x204
+#define CSR_VSTVEC          0x205
+#define CSR_VSSCRATCH       0x240
+#define CSR_VSEPC           0x241
+#define CSR_VSCAUSE         0x242
+#define CSR_VSTVAL          0x243
+#define CSR_VSIP            0x244
+#define CSR_VSATP           0x280
+
+#define CSR_MTINST          0x34a
+#define CSR_MTVAL2          0x34b
+
 /* Physical Memory Protection */
 #define CSR_PMPCFG0         0x3a0
 #define CSR_PMPCFG1         0x3a1
@@ -313,17 +333,6 @@
 #define CSR_MHPMCOUNTER30H  0xb9e
 #define CSR_MHPMCOUNTER31H  0xb9f
 
-/* Legacy Hypervisor Trap Setup (priv v1.9.1) */
-#define CSR_HIE             0x204
-#define CSR_HTVEC           0x205
-
-/* Legacy Hypervisor Trap Handling (priv v1.9.1) */
-#define CSR_HSCRATCH        0x240
-#define CSR_HEPC            0x241
-#define CSR_HCAUSE          0x242
-#define CSR_HBADADDR        0x243
-#define CSR_HIP             0x244
-
 /* Legacy Machine Protection and Translation (priv v1.9.1) */
 #define CSR_MBASE           0x380
 #define CSR_MBOUND          0x381
@@ -400,7 +409,6 @@
 
 /* hstatus CSR bits */
 #define HSTATUS_SPRV         0x00000001
-#define HSTATUS_STL          0x00000040
 #define HSTATUS_SPV          0x00000080
 #define HSTATUS_SP2P         0x00000100
 #define HSTATUS_SP2V         0x00000200
diff --git a/target/riscv/gdbstub.c b/target/riscv/gdbstub.c
index 1a7947e019..6d606f0d90 100644
--- a/target/riscv/gdbstub.c
+++ b/target/riscv/gdbstub.c
@@ -130,6 +130,8 @@ static int csr_register_map[] = {
     CSR_MCAUSE,
     CSR_MTVAL,
     CSR_MIP,
+    CSR_MTINST,
+    CSR_MTVAL2,
     CSR_PMPCFG0,
     CSR_PMPCFG1,
     CSR_PMPCFG2,
@@ -252,12 +254,11 @@ static int csr_register_map[] = {
     CSR_HEDELEG,
     CSR_HIDELEG,
     CSR_HIE,
-    CSR_HTVEC,
-    CSR_HSCRATCH,
-    CSR_HEPC,
-    CSR_HCAUSE,
-    CSR_HBADADDR,
+    CSR_HCOUNTEREN,
+    CSR_HTVAL,
     CSR_HIP,
+    CSR_HTINST,
+    CSR_HGATP,
     CSR_MBASE,
     CSR_MBOUND,
     CSR_MIBASE,
-- 
2.25.0

[PATCH v2 04/35] target/riscv: Add support for the new execption numbers

[Alistair Francis]

The v0.5 Hypervisor spec add new execption numbers, let's add support
for those.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.c        |  8 ++++++++
 target/riscv/cpu_bits.h   | 35 +++++++++++++++++++----------------
 target/riscv/cpu_helper.c |  7 +++++--
 target/riscv/csr.c        |  7 +++++--
 4 files changed, 37 insertions(+), 20 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index efbd676edb..2f62f5ea19 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -67,6 +67,14 @@ const char * const riscv_excp_names[] = {
     "load_page_fault",
     "reserved",
     "store_page_fault"
+    "reserved",
+    "reserved",
+    "reserved",
+    "reserved",
+    "guest_exec_page_fault",
+    "guest_load_page_fault",
+    "reserved",
+    "guest_store_page_fault"
 };
 
 const char * const riscv_intr_names[] = {
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 25c0fb258d..9ce73c36de 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -488,22 +488,25 @@
 #define DEFAULT_RSTVEC      0x1000
 
 /* Exception causes */
-#define EXCP_NONE                          -1 /* sentinel value */
-#define RISCV_EXCP_INST_ADDR_MIS           0x0
-#define RISCV_EXCP_INST_ACCESS_FAULT       0x1
-#define RISCV_EXCP_ILLEGAL_INST            0x2
-#define RISCV_EXCP_BREAKPOINT              0x3
-#define RISCV_EXCP_LOAD_ADDR_MIS           0x4
-#define RISCV_EXCP_LOAD_ACCESS_FAULT       0x5
-#define RISCV_EXCP_STORE_AMO_ADDR_MIS      0x6
-#define RISCV_EXCP_STORE_AMO_ACCESS_FAULT  0x7
-#define RISCV_EXCP_U_ECALL                 0x8
-#define RISCV_EXCP_S_ECALL                 0x9
-#define RISCV_EXCP_H_ECALL                 0xa
-#define RISCV_EXCP_M_ECALL                 0xb
-#define RISCV_EXCP_INST_PAGE_FAULT         0xc /* since: priv-1.10.0 */
-#define RISCV_EXCP_LOAD_PAGE_FAULT         0xd /* since: priv-1.10.0 */
-#define RISCV_EXCP_STORE_PAGE_FAULT        0xf /* since: priv-1.10.0 */
+#define EXCP_NONE                                -1 /* sentinel value */
+#define RISCV_EXCP_INST_ADDR_MIS                 0x0
+#define RISCV_EXCP_INST_ACCESS_FAULT             0x1
+#define RISCV_EXCP_ILLEGAL_INST                  0x2
+#define RISCV_EXCP_BREAKPOINT                    0x3
+#define RISCV_EXCP_LOAD_ADDR_MIS                 0x4
+#define RISCV_EXCP_LOAD_ACCESS_FAULT             0x5
+#define RISCV_EXCP_STORE_AMO_ADDR_MIS            0x6
+#define RISCV_EXCP_STORE_AMO_ACCESS_FAULT        0x7
+#define RISCV_EXCP_U_ECALL                       0x8
+#define RISCV_EXCP_S_ECALL                      0x9
+#define RISCV_EXCP_VS_ECALL                      0xa
+#define RISCV_EXCP_M_ECALL                       0xb
+#define RISCV_EXCP_INST_PAGE_FAULT               0xc /* since: priv-1.10.0 */
+#define RISCV_EXCP_LOAD_PAGE_FAULT               0xd /* since: priv-1.10.0 */
+#define RISCV_EXCP_STORE_PAGE_FAULT              0xf /* since: priv-1.10.0 */
+#define RISCV_EXCP_INST_GUEST_PAGE_FAULT         0x14
+#define RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT       0x15
+#define RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT  0x17
 
 #define RISCV_EXCP_INT_FLAG                0x80000000
 #define RISCV_EXCP_INT_MASK                0x7fffffff
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index b8e85d5b20..8f746fb06f 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -526,13 +526,16 @@ void riscv_cpu_do_interrupt(CPUState *cs)
     static const int ecall_cause_map[] = {
         [PRV_U] = RISCV_EXCP_U_ECALL,
         [PRV_S] = RISCV_EXCP_S_ECALL,
-        [PRV_H] = RISCV_EXCP_H_ECALL,
+        [PRV_H] = RISCV_EXCP_VS_ECALL,
         [PRV_M] = RISCV_EXCP_M_ECALL
     };
 
     if (!async) {
         /* set tval to badaddr for traps with address information */
         switch (cause) {
+        case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
+        case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
+        case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
         case RISCV_EXCP_INST_ADDR_MIS:
         case RISCV_EXCP_INST_ACCESS_FAULT:
         case RISCV_EXCP_LOAD_ADDR_MIS:
@@ -554,7 +557,7 @@ void riscv_cpu_do_interrupt(CPUState *cs)
         }
     }
 
-    trace_riscv_trap(env->mhartid, async, cause, env->pc, tval, cause < 16 ?
+    trace_riscv_trap(env->mhartid, async, cause, env->pc, tval, cause < 23 ?
         (async ? riscv_intr_names : riscv_excp_names)[cause] : "(unknown)");
 
     if (env->priv <= PRV_S &&
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 0e34c292c5..ca27359c7e 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -242,11 +242,14 @@ static const target_ulong delegable_excps =
     (1ULL << (RISCV_EXCP_STORE_AMO_ACCESS_FAULT)) |
     (1ULL << (RISCV_EXCP_U_ECALL)) |
     (1ULL << (RISCV_EXCP_S_ECALL)) |
-    (1ULL << (RISCV_EXCP_H_ECALL)) |
+    (1ULL << (RISCV_EXCP_VS_ECALL)) |
     (1ULL << (RISCV_EXCP_M_ECALL)) |
     (1ULL << (RISCV_EXCP_INST_PAGE_FAULT)) |
     (1ULL << (RISCV_EXCP_LOAD_PAGE_FAULT)) |
-    (1ULL << (RISCV_EXCP_STORE_PAGE_FAULT));
+    (1ULL << (RISCV_EXCP_STORE_PAGE_FAULT)) |
+    (1ULL << (RISCV_EXCP_INST_GUEST_PAGE_FAULT)) |
+    (1ULL << (RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT)) |
+    (1ULL << (RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT));
 static const target_ulong sstatus_v1_9_mask = SSTATUS_SIE | SSTATUS_SPIE |
     SSTATUS_UIE | SSTATUS_UPIE | SSTATUS_SPP | SSTATUS_FS | SSTATUS_XS |
     SSTATUS_SUM | SSTATUS_SD;
-- 
2.25.0

[PATCH v2 05/35] target/riscv: Rename the H irqs to VS irqs

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.c      |  6 +++---
 target/riscv/cpu_bits.h | 12 ++++++------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 2f62f5ea19..f7a35c74c2 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -80,14 +80,14 @@ const char * const riscv_excp_names[] = {
 const char * const riscv_intr_names[] = {
     "u_software",
     "s_software",
-    "h_software",
+    "vs_software",
     "m_software",
     "u_timer",
     "s_timer",
-    "h_timer",
+    "vs_timer",
     "m_timer",
     "u_external",
-    "s_external",
+    "vs_external",
     "h_external",
     "m_external",
     "reserved",
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 9ce73c36de..eeaa03c0f8 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -514,29 +514,29 @@
 /* Interrupt causes */
 #define IRQ_U_SOFT                         0
 #define IRQ_S_SOFT                         1
-#define IRQ_H_SOFT                         2  /* reserved */
+#define IRQ_VS_SOFT                        2
 #define IRQ_M_SOFT                         3
 #define IRQ_U_TIMER                        4
 #define IRQ_S_TIMER                        5
-#define IRQ_H_TIMER                        6  /* reserved */
+#define IRQ_VS_TIMER                       6
 #define IRQ_M_TIMER                        7
 #define IRQ_U_EXT                          8
 #define IRQ_S_EXT                          9
-#define IRQ_H_EXT                          10 /* reserved */
+#define IRQ_VS_EXT                         10
 #define IRQ_M_EXT                          11
 
 /* mip masks */
 #define MIP_USIP                           (1 << IRQ_U_SOFT)
 #define MIP_SSIP                           (1 << IRQ_S_SOFT)
-#define MIP_HSIP                           (1 << IRQ_H_SOFT)
+#define MIP_VSSIP                          (1 << IRQ_VS_SOFT)
 #define MIP_MSIP                           (1 << IRQ_M_SOFT)
 #define MIP_UTIP                           (1 << IRQ_U_TIMER)
 #define MIP_STIP                           (1 << IRQ_S_TIMER)
-#define MIP_HTIP                           (1 << IRQ_H_TIMER)
+#define MIP_VSTIP                          (1 << IRQ_VS_TIMER)
 #define MIP_MTIP                           (1 << IRQ_M_TIMER)
 #define MIP_UEIP                           (1 << IRQ_U_EXT)
 #define MIP_SEIP                           (1 << IRQ_S_EXT)
-#define MIP_HEIP                           (1 << IRQ_H_EXT)
+#define MIP_VSEIP                          (1 << IRQ_VS_EXT)
 #define MIP_MEIP                           (1 << IRQ_M_EXT)
 
 /* sip masks */
-- 
2.25.0

[PATCH v2 06/35] target/riscv: Add the virtulisation mode

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h        |  4 ++++
 target/riscv/cpu_bits.h   |  3 +++
 target/riscv/cpu_helper.c | 18 ++++++++++++++++++
 3 files changed, 25 insertions(+)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index c7f7ae5c38..a9cbd8584e 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -117,6 +117,8 @@ struct CPURISCVState {
 
 #ifndef CONFIG_USER_ONLY
     target_ulong priv;
+    /* This contains QEMU specific information about the virt state. */
+    target_ulong virt;
     target_ulong resetvec;
 
     target_ulong mhartid;
@@ -269,6 +271,8 @@ int riscv_cpu_gdb_read_register(CPUState *cpu, uint8_t *buf, int reg);
 int riscv_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
 bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request);
 bool riscv_cpu_fp_enabled(CPURISCVState *env);
+bool riscv_cpu_virt_enabled(CPURISCVState *env);
+void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable);
 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch);
 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
 void  riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index eeaa03c0f8..2cdb0de4fe 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -430,6 +430,9 @@
 #define PRV_H 2 /* Reserved */
 #define PRV_M 3
 
+/* Virtulisation Register Fields */
+#define VIRT_ONOFF          1
+
 /* RV32 satp CSR field masks */
 #define SATP32_MODE         0x80000000
 #define SATP32_ASID         0x7fc00000
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 8f746fb06f..5844e543f3 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -82,6 +82,24 @@ bool riscv_cpu_fp_enabled(CPURISCVState *env)
     return false;
 }
 
+bool riscv_cpu_virt_enabled(CPURISCVState *env)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return false;
+    }
+
+    return get_field(env->virt, VIRT_ONOFF);
+}
+
+void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return;
+    }
+
+    env->virt = set_field(env->virt, VIRT_ONOFF, enable);
+}
+
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
 {
     CPURISCVState *env = &cpu->env;
-- 
2.25.0

[PATCH v2 07/35] target/riscv: Add the force HS exception mode

[Alistair Francis]

Add a FORCE_HS_EXCEP mode to the RISC-V virtulisation status. This bit
specifies if an exeption should be taken to HS mode no matter the
current delegation status. This is used when an exeption must be taken
to HS mode, such as when handling interrupts.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.h        |  2 ++
 target/riscv/cpu_bits.h   |  6 ++++++
 target/riscv/cpu_helper.c | 18 ++++++++++++++++++
 3 files changed, 26 insertions(+)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index a9cbd8584e..42720d65f9 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -273,6 +273,8 @@ bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request);
 bool riscv_cpu_fp_enabled(CPURISCVState *env);
 bool riscv_cpu_virt_enabled(CPURISCVState *env);
 void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable);
+bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env);
+void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable);
 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch);
 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
 void  riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 2cdb0de4fe..ad6479796c 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -432,6 +432,12 @@
 
 /* Virtulisation Register Fields */
 #define VIRT_ONOFF          1
+/* This is used to save state for when we take an exception. If this is set
+ * that means that we want to force a HS level exception (no matter what the
+ * delegation is set to). This will occur for things such as a second level
+ * page table fault.
+ */
+#define FORCE_HS_EXCEP      2
 
 /* RV32 satp CSR field masks */
 #define SATP32_MODE         0x80000000
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 5844e543f3..1e28103500 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -100,6 +100,24 @@ void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
     env->virt = set_field(env->virt, VIRT_ONOFF, enable);
 }
 
+bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return false;
+    }
+
+    return get_field(env->virt, FORCE_HS_EXCEP);
+}
+
+void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable)
+{
+    if (!riscv_has_ext(env, RVH)) {
+        return;
+    }
+
+    env->virt = set_field(env->virt, FORCE_HS_EXCEP, enable);
+}
+
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
 {
     CPURISCVState *env = &cpu->env;
-- 
2.25.0

[PATCH v2 08/35] target/riscv: Fix CSR perm checking for HS mode

[Alistair Francis]

Update the CSR permission checking to work correctly when we are in
HS-mode.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/csr.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index ca27359c7e..c63b2f980c 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -801,12 +801,22 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
 
     /* check privileges and return -1 if check fails */
 #if !defined(CONFIG_USER_ONLY)
-    int csr_priv = get_field(csrno, 0x300);
+    int effective_priv = env->priv;
     int read_only = get_field(csrno, 0xC00) == 3;
-    if ((!env->debugger) && (env->priv < csr_priv)) {
-        return -1;
+
+    if (riscv_has_ext(env, RVH) &&
+        env->priv == PRV_S &&
+        !riscv_cpu_virt_enabled(env)) {
+        /*
+         * We are in S mode without virtualisation, therefore we are in HS Mode.
+         * Add 1 to the effective privledge level to allow us to access the
+         * Hypervisor CSRs.
+         */
+        effective_priv++;
     }
-    if (write_mask && read_only) {
+
+    if ((write_mask && read_only) ||
+        (!env->debugger && (effective_priv < get_field(csrno, 0x300)))) {
         return -1;
     }
 #endif
-- 
2.25.0

[PATCH v2 09/35] target/riscv: Print priv and virt in disas log

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
---
 target/riscv/translate.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 14dc71156b..afa2d6eea2 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -808,7 +808,15 @@ static void riscv_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu)
 
 static void riscv_tr_disas_log(const DisasContextBase *dcbase, CPUState *cpu)
 {
+#ifndef CONFIG_USER_ONLY
+    RISCVCPU *rvcpu = RISCV_CPU(cpu);
+    CPURISCVState *env = &rvcpu->env;
+#endif
+
     qemu_log("IN: %s\n", lookup_symbol(dcbase->pc_first));
+#ifndef CONFIG_USER_ONLY
+    qemu_log("Priv: "TARGET_FMT_ld"; Virt: "TARGET_FMT_ld"\n", env->priv, env->virt);
+#endif
     log_target_disas(cpu, dcbase->pc_first, dcbase->tb->size);
 }
 
-- 
2.25.0

[PATCH v2 10/35] target/riscv: Dump Hypervisor registers if enabled

[Alistair Francis]

Dump the Hypervisor registers and the current Hypervisor state.

While we are editing this code let's also dump stvec and scause.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
---
 target/riscv/cpu.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index f7a35c74c2..44ad768a84 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -228,17 +228,50 @@ static void riscv_cpu_dump_state(CPUState *cs, FILE *f, int flags)
     CPURISCVState *env = &cpu->env;
     int i;
 
+#if !defined(CONFIG_USER_ONLY)
+    if (riscv_has_ext(env, RVH)) {
+        qemu_fprintf(f, " %s %d\n", "V      =  ", riscv_cpu_virt_enabled(env));
+    }
+#endif
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "pc      ", env->pc);
 #ifndef CONFIG_USER_ONLY
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mhartid ", env->mhartid);
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ", env->mstatus);
+    if (riscv_has_ext(env, RVH)) {
+        qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "hstatus ", env->hstatus);
+        qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "vsstatus ", env->vsstatus);
+    }
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mip     ", env->mip);
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mie     ", env->mie);
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mideleg ", env->mideleg);
+    if (riscv_has_ext(env, RVH)) {
+        qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "hideleg ", env->hideleg);
+    }
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "medeleg ", env->medeleg);
+    if (riscv_has_ext(env, RVH)) {
+        qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "hedeleg ", env->hedeleg);
+    }
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mtvec   ", env->mtvec);
+    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "stvec   ", env->stvec);
+    if (riscv_has_ext(env, RVH)) {
+        qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "vstvec  ", env->vstvec);
+    }
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mepc    ", env->mepc);
+    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "sepc    ", env->sepc);
+    if (riscv_has_ext(env, RVH)) {
+        qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "vsepc   ", env->vsepc);
+    }
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mcause  ", env->mcause);
+    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "scause  ", env->scause);
+    if (riscv_has_ext(env, RVH)) {
+        qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "vscause ", env->vscause);
+    }
+    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mtval ", env->mtval);
+    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "stval ", env->sbadaddr);
+    if (riscv_has_ext(env, RVH)) {
+        qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "htval ", env->htval);
+        qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mtval2 ", env->mtval2);
+    }
 #endif
 
     for (i = 0; i < 32; i++) {
-- 
2.25.0

[PATCH v2 11/35] target/riscv: Add Hypervisor CSR access functions

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/csr.c | 136 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 134 insertions(+), 2 deletions(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index c63b2f980c..bee639e92e 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -98,6 +98,20 @@ static int smode(CPURISCVState *env, int csrno)
     return -!riscv_has_ext(env, RVS);
 }
 
+static int hmode(CPURISCVState *env, int csrno)
+{
+    if (riscv_has_ext(env, RVS) &&
+        riscv_has_ext(env, RVH)) {
+        /* Hypervisor extension is supported */
+        if ((env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) ||
+            env->priv == PRV_M) {
+            return 0;
+        }
+    }
+
+    return -1;
+}
+
 static int pmp(CPURISCVState *env, int csrno)
 {
     return -!riscv_feature(env, RISCV_FEATURE_PMP);
@@ -226,8 +240,9 @@ static int read_timeh(CPURISCVState *env, int csrno, target_ulong *val)
 
 /* Machine constants */
 
-#define M_MODE_INTERRUPTS (MIP_MSIP | MIP_MTIP | MIP_MEIP)
-#define S_MODE_INTERRUPTS (MIP_SSIP | MIP_STIP | MIP_SEIP)
+#define M_MODE_INTERRUPTS  (MIP_MSIP | MIP_MTIP | MIP_MEIP)
+#define S_MODE_INTERRUPTS  (MIP_SSIP | MIP_STIP | MIP_SEIP)
+#define VS_MODE_INTERRUPTS (MIP_VSSIP | MIP_VSTIP | MIP_VSEIP)
 
 static const target_ulong delegable_ints = S_MODE_INTERRUPTS;
 static const target_ulong all_ints = M_MODE_INTERRUPTS | S_MODE_INTERRUPTS;
@@ -257,6 +272,7 @@ static const target_ulong sstatus_v1_10_mask = SSTATUS_SIE | SSTATUS_SPIE |
     SSTATUS_UIE | SSTATUS_UPIE | SSTATUS_SPP | SSTATUS_FS | SSTATUS_XS |
     SSTATUS_SUM | SSTATUS_MXR | SSTATUS_SD;
 static const target_ulong sip_writable_mask = SIP_SSIP | MIP_USIP | MIP_UEIP;
+static const target_ulong hip_writable_mask = MIP_VSSIP | MIP_VSTIP | MIP_VSEIP;
 
 #if defined(TARGET_RISCV32)
 static const char valid_vm_1_09[16] = {
@@ -756,6 +772,112 @@ static int write_satp(CPURISCVState *env, int csrno, target_ulong val)
     return 0;
 }
 
+/* Hypervisor Extensions */
+static int read_hstatus(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->hstatus;
+    return 0;
+}
+
+static int write_hstatus(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->hstatus = val;
+    return 0;
+}
+
+static int read_hedeleg(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->hedeleg;
+    return 0;
+}
+
+static int write_hedeleg(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->hedeleg = val;
+    return 0;
+}
+
+static int read_hideleg(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->hideleg;
+    return 0;
+}
+
+static int write_hideleg(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->hideleg = val;
+    return 0;
+}
+
+static int rmw_hip(CPURISCVState *env, int csrno, target_ulong *ret_value,
+                   target_ulong new_value, target_ulong write_mask)
+{
+    int ret = rmw_mip(env, 0, ret_value, new_value,
+                      write_mask & hip_writable_mask);
+
+    return ret;
+}
+
+static int read_hie(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->mie & VS_MODE_INTERRUPTS;
+    return 0;
+}
+
+static int write_hie(CPURISCVState *env, int csrno, target_ulong val)
+{
+    target_ulong newval = (env->mie & ~VS_MODE_INTERRUPTS) | (val & VS_MODE_INTERRUPTS);
+    return write_mie(env, CSR_MIE, newval);
+}
+
+static int read_hcounteren(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->hcounteren;
+    return 0;
+}
+
+static int write_hcounteren(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->hcounteren = val;
+    return 0;
+}
+
+static int read_htval(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->htval;
+    return 0;
+}
+
+static int write_htval(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->htval = val;
+    return 0;
+}
+
+static int read_htinst(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->htinst;
+    return 0;
+}
+
+static int write_htinst(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->htinst = val;
+    return 0;
+}
+
+static int read_hgatp(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->hgatp;
+    return 0;
+}
+
+static int write_hgatp(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->hgatp = val;
+    return 0;
+}
+
 /* Physical Memory Protection */
 static int read_pmpcfg(CPURISCVState *env, int csrno, target_ulong *val)
 {
@@ -959,6 +1081,16 @@ static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     /* Supervisor Protection and Translation */
     [CSR_SATP] =                { smode, read_satp,        write_satp        },
 
+    [CSR_HSTATUS] =             { hmode,   read_hstatus,     write_hstatus    },
+    [CSR_HEDELEG] =             { hmode,   read_hedeleg,     write_hedeleg    },
+    [CSR_HIDELEG] =             { hmode,   read_hideleg,     write_hideleg    },
+    [CSR_HIP] =                 { hmode,   NULL,     NULL,     rmw_hip        },
+    [CSR_HIE] =                 { hmode,   read_hie,         write_hie        },
+    [CSR_HCOUNTEREN] =          { hmode,   read_hcounteren,  write_hcounteren },
+    [CSR_HTVAL] =               { hmode,   read_htval,       write_htval      },
+    [CSR_HTINST] =              { hmode,   read_htinst,      write_htinst     },
+    [CSR_HGATP] =               { hmode,   read_hgatp,       write_hgatp      },
+
     /* Physical Memory Protection */
     [CSR_PMPCFG0  ... CSR_PMPADDR9] =  { pmp,   read_pmpcfg,  write_pmpcfg   },
     [CSR_PMPADDR0 ... CSR_PMPADDR15] = { pmp,   read_pmpaddr, write_pmpaddr  },
-- 
2.25.0

[PATCH v2 12/35] target/riscv: Add Hypervisor virtual CSRs accesses

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
---
 target/riscv/csr.c | 116 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index bee639e92e..3fa8d2cfda 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -273,6 +273,7 @@ static const target_ulong sstatus_v1_10_mask = SSTATUS_SIE | SSTATUS_SPIE |
     SSTATUS_SUM | SSTATUS_MXR | SSTATUS_SD;
 static const target_ulong sip_writable_mask = SIP_SSIP | MIP_USIP | MIP_UEIP;
 static const target_ulong hip_writable_mask = MIP_VSSIP | MIP_VSTIP | MIP_VSEIP;
+static const target_ulong vsip_writable_mask = MIP_VSSIP;
 
 #if defined(TARGET_RISCV32)
 static const char valid_vm_1_09[16] = {
@@ -878,6 +879,111 @@ static int write_hgatp(CPURISCVState *env, int csrno, target_ulong val)
     return 0;
 }
 
+/* Virtual CSR Registers */
+static int read_vsstatus(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vsstatus;
+    return 0;
+}
+
+static int write_vsstatus(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vsstatus = val;
+    return 0;
+}
+
+static int rmw_vsip(CPURISCVState *env, int csrno, target_ulong *ret_value,
+                    target_ulong new_value, target_ulong write_mask)
+{
+    int ret = rmw_mip(env, 0, ret_value, new_value,
+                      write_mask & env->mideleg & vsip_writable_mask);
+    return ret;
+}
+
+static int read_vsie(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->mie & env->mideleg & VS_MODE_INTERRUPTS;
+    return 0;
+}
+
+static int write_vsie(CPURISCVState *env, int csrno, target_ulong val)
+{
+    target_ulong newval = (env->mie & ~env->mideleg) | (val & env->mideleg & MIP_VSSIP);
+    return write_mie(env, CSR_MIE, newval);
+}
+
+static int read_vstvec(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vstvec;
+    return 0;
+}
+
+static int write_vstvec(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vstvec = val;
+    return 0;
+}
+
+static int read_vsscratch(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vsscratch;
+    return 0;
+}
+
+static int write_vsscratch(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vsscratch = val;
+    return 0;
+}
+
+static int read_vsepc(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vsepc;
+    return 0;
+}
+
+static int write_vsepc(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vsepc = val;
+    return 0;
+}
+
+static int read_vscause(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vscause;
+    return 0;
+}
+
+static int write_vscause(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vscause = val;
+    return 0;
+}
+
+static int read_vstval(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vstval;
+    return 0;
+}
+
+static int write_vstval(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vstval = val;
+    return 0;
+}
+
+static int read_vsatp(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vsatp;
+    return 0;
+}
+
+static int write_vsatp(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vsatp = val;
+    return 0;
+}
+
 /* Physical Memory Protection */
 static int read_pmpcfg(CPURISCVState *env, int csrno, target_ulong *val)
 {
@@ -1091,6 +1197,16 @@ static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_HTINST] =              { hmode,   read_htinst,      write_htinst     },
     [CSR_HGATP] =               { hmode,   read_hgatp,       write_hgatp      },
 
+    [CSR_VSSTATUS] =            { hmode,   read_vsstatus,    write_vsstatus   },
+    [CSR_VSIP] =                { hmode,   NULL,     NULL,     rmw_vsip       },
+    [CSR_VSIE] =                { hmode,   read_vsie,        write_vsie       },
+    [CSR_VSTVEC] =              { hmode,   read_vstvec,      write_vstvec     },
+    [CSR_VSSCRATCH] =           { hmode,   read_vsscratch,   write_vsscratch  },
+    [CSR_VSEPC] =               { hmode,   read_vsepc,       write_vsepc      },
+    [CSR_VSCAUSE] =             { hmode,   read_vscause,     write_vscause    },
+    [CSR_VSTVAL] =              { hmode,   read_vstval,      write_vstval     },
+    [CSR_VSATP] =               { hmode,   read_vsatp,       write_vsatp      },
+
     /* Physical Memory Protection */
     [CSR_PMPCFG0  ... CSR_PMPADDR9] =  { pmp,   read_pmpcfg,  write_pmpcfg   },
     [CSR_PMPADDR0 ... CSR_PMPADDR15] = { pmp,   read_pmpaddr, write_pmpaddr  },
-- 
2.25.0

[PATCH v2 13/35] target/riscv: Add Hypervisor machine CSRs accesses

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/csr.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 3fa8d2cfda..f7333286bd 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -984,6 +984,30 @@ static int write_vsatp(CPURISCVState *env, int csrno, target_ulong val)
     return 0;
 }
 
+static int read_mtval2(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->mtval2;
+    return 0;
+}
+
+static int write_mtval2(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->mtval2 = val;
+    return 0;
+}
+
+static int read_mtinst(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->mtinst;
+    return 0;
+}
+
+static int write_mtinst(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->mtinst = val;
+    return 0;
+}
+
 /* Physical Memory Protection */
 static int read_pmpcfg(CPURISCVState *env, int csrno, target_ulong *val)
 {
@@ -1207,6 +1231,9 @@ static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_VSTVAL] =              { hmode,   read_vstval,      write_vstval     },
     [CSR_VSATP] =               { hmode,   read_vsatp,       write_vsatp      },
 
+    [CSR_MTVAL2] =              { hmode,   read_mtval2,      write_mtval2     },
+    [CSR_MTINST] =              { hmode,   read_mtinst,      write_mtinst     },
+
     /* Physical Memory Protection */
     [CSR_PMPCFG0  ... CSR_PMPADDR9] =  { pmp,   read_pmpcfg,  write_pmpcfg   },
     [CSR_PMPADDR0 ... CSR_PMPADDR15] = { pmp,   read_pmpaddr, write_pmpaddr  },
-- 
2.25.0

[PATCH v2 14/35] target/riscv: Add virtual register swapping function

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h        | 11 +++++++
 target/riscv/cpu_bits.h   |  7 +++++
 target/riscv/cpu_helper.c | 61 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 42720d65f9..5b889a0065 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -125,6 +125,7 @@ struct CPURISCVState {
     target_ulong mstatus;
 
     target_ulong mip;
+
     uint32_t miclaim;
 
     target_ulong mie;
@@ -166,6 +167,15 @@ struct CPURISCVState {
     target_ulong mtval2;
     target_ulong mtinst;
 
+    /* HS Backup CSRs */
+    target_ulong stvec_hs;
+    target_ulong sscratch_hs;
+    target_ulong sepc_hs;
+    target_ulong scause_hs;
+    target_ulong stval_hs;
+    target_ulong satp_hs;
+    target_ulong mstatus_hs;
+
     target_ulong scounteren;
     target_ulong mcounteren;
 
@@ -296,6 +306,7 @@ void riscv_cpu_list(void);
 #define cpu_mmu_index riscv_cpu_mmu_index
 
 #ifndef CONFIG_USER_ONLY
+void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env);
 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts);
 uint32_t riscv_cpu_update_mip(RISCVCPU *cpu, uint32_t mask, uint32_t value);
 #define BOOL_TO_MASK(x) (-!!(x)) /* helper for riscv_cpu_update_mip value */
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index ad6479796c..a24654d137 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -553,4 +553,11 @@
 #define SIP_STIP                           MIP_STIP
 #define SIP_SEIP                           MIP_SEIP
 
+/* MIE masks */
+#define MIE_SEIE                           (1 << IRQ_S_EXT)
+#define MIE_UEIE                           (1 << IRQ_U_EXT)
+#define MIE_STIE                           (1 << IRQ_S_TIMER)
+#define MIE_UTIE                           (1 << IRQ_U_TIMER)
+#define MIE_SSIE                           (1 << IRQ_S_SOFT)
+#define MIE_USIE                           (1 << IRQ_U_SOFT)
 #endif
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 1e28103500..e9d75b45d6 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -82,6 +82,67 @@ bool riscv_cpu_fp_enabled(CPURISCVState *env)
     return false;
 }
 
+void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
+{
+    target_ulong mstatus_mask = MSTATUS_MXR | MSTATUS_SUM | MSTATUS_FS |
+                                MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE;
+    bool current_virt = riscv_cpu_virt_enabled(env);
+
+    g_assert(riscv_has_ext(env, RVH));
+
+#if defined(TARGET_RISCV64)
+    mstatus_mask |= MSTATUS64_UXL;
+#endif
+
+    if (current_virt) {
+        /* Current V=1 and we are about to change to V=0 */
+        env->vsstatus = env->mstatus & mstatus_mask;
+        env->mstatus &= ~mstatus_mask;
+        env->mstatus |= env->mstatus_hs;
+
+        env->vstvec = env->stvec;
+        env->stvec = env->stvec_hs;
+
+        env->vsscratch = env->sscratch;
+        env->sscratch = env->sscratch_hs;
+
+        env->vsepc = env->sepc;
+        env->sepc = env->sepc_hs;
+
+        env->vscause = env->scause;
+        env->scause = env->scause_hs;
+
+        env->vstval = env->sbadaddr;
+        env->sbadaddr = env->stval_hs;
+
+        env->vsatp = env->satp;
+        env->satp = env->satp_hs;
+    } else {
+        /* Current V=0 and we are about to change to V=1 */
+        env->mstatus_hs = env->mstatus & mstatus_mask;
+        env->mstatus &= ~mstatus_mask;
+        env->mstatus |= env->vsstatus;
+
+        env->stvec_hs = env->stvec;
+        env->stvec = env->vstvec;
+
+        env->sscratch_hs = env->sscratch;
+        env->sscratch = env->vsscratch;
+
+        env->sepc_hs = env->sepc;
+        env->sepc = env->vsepc;
+
+        env->scause_hs = env->scause;
+        env->scause = env->vscause;
+
+        env->stval_hs = env->sbadaddr;
+        env->sbadaddr = env->vstval;
+
+        env->satp_hs = env->satp;
+        env->satp = env->vsatp;
+    }
+}
+
 bool riscv_cpu_virt_enabled(CPURISCVState *env)
 {
     if (!riscv_has_ext(env, RVH)) {
-- 
2.25.0

[PATCH v2 15/35] target/riscv: Set VS bits in mideleg for Hyp extension

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/csr.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index f7333286bd..c0e942684d 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -448,6 +448,9 @@ static int read_mideleg(CPURISCVState *env, int csrno, target_ulong *val)
 static int write_mideleg(CPURISCVState *env, int csrno, target_ulong val)
 {
     env->mideleg = (env->mideleg & ~delegable_ints) | (val & delegable_ints);
+    if (riscv_has_ext(env, RVH)) {
+        env->mideleg |= VS_MODE_INTERRUPTS;
+    }
     return 0;
 }
 
-- 
2.25.0

[PATCH v2 16/35] target/riscv: Extend the MIE CSR to support virtulisation

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/csr.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index c0e942684d..918678789a 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -244,8 +244,10 @@ static int read_timeh(CPURISCVState *env, int csrno, target_ulong *val)
 #define S_MODE_INTERRUPTS  (MIP_SSIP | MIP_STIP | MIP_SEIP)
 #define VS_MODE_INTERRUPTS (MIP_VSSIP | MIP_VSTIP | MIP_VSEIP)
 
-static const target_ulong delegable_ints = S_MODE_INTERRUPTS;
-static const target_ulong all_ints = M_MODE_INTERRUPTS | S_MODE_INTERRUPTS;
+static const target_ulong delegable_ints = S_MODE_INTERRUPTS |
+                                           VS_MODE_INTERRUPTS;
+static const target_ulong all_ints = M_MODE_INTERRUPTS | S_MODE_INTERRUPTS |
+                                     VS_MODE_INTERRUPTS;
 static const target_ulong delegable_excps =
     (1ULL << (RISCV_EXCP_INST_ADDR_MIS)) |
     (1ULL << (RISCV_EXCP_INST_ACCESS_FAULT)) |
@@ -630,13 +632,27 @@ static int write_sstatus(CPURISCVState *env, int csrno, target_ulong val)
 
 static int read_sie(CPURISCVState *env, int csrno, target_ulong *val)
 {
-    *val = env->mie & env->mideleg;
+    if (riscv_cpu_virt_enabled(env)) {
+        /* Tell the guest the VS bits, shifted to the S bit locations */
+        *val = (env->mie & env->mideleg & VS_MODE_INTERRUPTS) >> 1;
+    } else {
+        *val = env->mie & env->mideleg;
+    }
     return 0;
 }
 
 static int write_sie(CPURISCVState *env, int csrno, target_ulong val)
 {
-    target_ulong newval = (env->mie & ~env->mideleg) | (val & env->mideleg);
+    target_ulong newval;
+
+    if (riscv_cpu_virt_enabled(env)) {
+        /* Shift the guests S bits to VS */
+        newval = (env->mie & ~VS_MODE_INTERRUPTS) |
+                 ((val << 1) & VS_MODE_INTERRUPTS);
+    } else {
+        newval = (env->mie & ~S_MODE_INTERRUPTS) | (val & S_MODE_INTERRUPTS);
+    }
+
     return write_mie(env, CSR_MIE, newval);
 }
 
-- 
2.25.0

[PATCH v2 17/35] target/riscv: Extend the SIP CSR to support virtulisation

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/csr.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 918678789a..2e6700bbeb 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -743,8 +743,19 @@ static int write_sbadaddr(CPURISCVState *env, int csrno, target_ulong val)
 static int rmw_sip(CPURISCVState *env, int csrno, target_ulong *ret_value,
                    target_ulong new_value, target_ulong write_mask)
 {
-    int ret = rmw_mip(env, CSR_MSTATUS, ret_value, new_value,
+    int ret;
+
+    if (riscv_cpu_virt_enabled(env)) {
+        /* Shift the new values to line up with the VS bits */
+        ret = rmw_mip(env, CSR_MSTATUS, ret_value, new_value << 1,
+                      (write_mask & sip_writable_mask) << 1 & env->mideleg);
+        ret &= vsip_writable_mask;
+        ret >>= 1;
+    } else {
+        ret = rmw_mip(env, CSR_MSTATUS, ret_value, new_value,
                       write_mask & env->mideleg & sip_writable_mask);
+    }
+
     *ret_value &= env->mideleg;
     return ret;
 }
-- 
2.25.0

[PATCH v2 18/35] target/riscv: Add support for virtual interrupt setting

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu_helper.c | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index e9d75b45d6..3984a1f1ac 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -37,13 +37,36 @@ int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
 #ifndef CONFIG_USER_ONLY
 static int riscv_cpu_local_irq_pending(CPURISCVState *env)
 {
+    target_ulong irqs;
+
     target_ulong mstatus_mie = get_field(env->mstatus, MSTATUS_MIE);
     target_ulong mstatus_sie = get_field(env->mstatus, MSTATUS_SIE);
-    target_ulong pending = env->mip & env->mie;
-    target_ulong mie = env->priv < PRV_M || (env->priv == PRV_M && mstatus_mie);
-    target_ulong sie = env->priv < PRV_S || (env->priv == PRV_S && mstatus_sie);
-    target_ulong irqs = (pending & ~env->mideleg & -mie) |
-                        (pending &  env->mideleg & -sie);
+    target_ulong hs_mstatus_sie = get_field(env->mstatus_hs, MSTATUS_SIE);
+
+    target_ulong pending = env->mip & env->mie &
+                               ~(MIP_VSSIP | MIP_VSTIP | MIP_VSEIP);
+    target_ulong vspending = (env->mip & env->mie &
+                              (MIP_VSSIP | MIP_VSTIP | MIP_VSEIP)) >> 1;
+
+    target_ulong mie    = env->priv < PRV_M ||
+                          (env->priv == PRV_M && mstatus_mie);
+    target_ulong sie    = env->priv < PRV_S ||
+                          (env->priv == PRV_S && mstatus_sie);
+    target_ulong hs_sie = env->priv < PRV_S ||
+                          (env->priv == PRV_S && hs_mstatus_sie);
+
+    if (riscv_cpu_virt_enabled(env)) {
+        target_ulong pending_hs_irq = pending & -hs_sie;
+
+        if (pending_hs_irq) {
+            riscv_cpu_set_force_hs_excep(env, FORCE_HS_EXCEP);
+            return ctz64(pending_hs_irq);
+        }
+
+        pending = vspending;
+    }
+
+    irqs = (pending & ~env->mideleg & -mie) | (pending &  env->mideleg & -sie);
 
     if (irqs) {
         return ctz64(irqs); /* since non-zero */
-- 
2.25.0

[PATCH v2 19/35] target/ricsv: Flush the TLB on virtulisation mode changes

[Alistair Francis]

To ensure our TLB isn't out-of-date we flush it on all virt mode
changes. Unlike priv mode this isn't saved in the mmu_idx as all
guests share V=1. The easiest option is just to flush on all changes.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
---
 target/riscv/cpu_helper.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 3984a1f1ac..98017df33b 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -181,6 +181,11 @@ void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
         return;
     }
 
+    /* Flush the TLB on all virt mode changes. */
+    if (get_field(env->virt, VIRT_ONOFF) != enable) {
+        tlb_flush(env_cpu(env));
+    }
+
     env->virt = set_field(env->virt, VIRT_ONOFF, enable);
 }
 
-- 
2.25.0

[PATCH v2 20/35] target/riscv: Generate illegal instruction on WFI when V=1

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
---
 target/riscv/op_helper.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index e87c9115bc..455eb28907 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -130,9 +130,10 @@ void helper_wfi(CPURISCVState *env)
 {
     CPUState *cs = env_cpu(env);
 
-    if (env->priv == PRV_S &&
+    if ((env->priv == PRV_S &&
         env->priv_ver >= PRIV_VERSION_1_10_0 &&
-        get_field(env->mstatus, MSTATUS_TW)) {
+        get_field(env->mstatus, MSTATUS_TW)) ||
+        riscv_cpu_virt_enabled(env)) {
         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
     } else {
         cs->halted = 1;
-- 
2.25.0

[PATCH v2 21/35] target/riscv: Add hypvervisor trap support

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu_helper.c | 69 +++++++++++++++++++++++++++++++++------
 1 file changed, 59 insertions(+), 10 deletions(-)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 98017df33b..e7728cb0ca 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -639,6 +639,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
 
     RISCVCPU *cpu = RISCV_CPU(cs);
     CPURISCVState *env = &cpu->env;
+    bool force_hs_execp = riscv_cpu_force_hs_excep_enabled(env);
+    target_ulong s;
 
     /* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
      * so we mask off the MSB and separate into trap type and cause.
@@ -648,19 +650,14 @@ void riscv_cpu_do_interrupt(CPUState *cs)
     target_ulong deleg = async ? env->mideleg : env->medeleg;
     target_ulong tval = 0;
 
-    static const int ecall_cause_map[] = {
-        [PRV_U] = RISCV_EXCP_U_ECALL,
-        [PRV_S] = RISCV_EXCP_S_ECALL,
-        [PRV_H] = RISCV_EXCP_VS_ECALL,
-        [PRV_M] = RISCV_EXCP_M_ECALL
-    };
-
     if (!async) {
         /* set tval to badaddr for traps with address information */
         switch (cause) {
         case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
         case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
         case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
+            force_hs_execp = true;
+            /* fallthrough */
         case RISCV_EXCP_INST_ADDR_MIS:
         case RISCV_EXCP_INST_ACCESS_FAULT:
         case RISCV_EXCP_LOAD_ADDR_MIS:
@@ -678,7 +675,16 @@ void riscv_cpu_do_interrupt(CPUState *cs)
         /* ecall is dispatched as one cause so translate based on mode */
         if (cause == RISCV_EXCP_U_ECALL) {
             assert(env->priv <= 3);
-            cause = ecall_cause_map[env->priv];
+
+            if (env->priv == PRV_M) {
+                cause = RISCV_EXCP_M_ECALL;
+            } else if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
+                cause = RISCV_EXCP_VS_ECALL;
+            } else if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) {
+                cause = RISCV_EXCP_S_ECALL;
+            } else if (env->priv == PRV_U) {
+                cause = RISCV_EXCP_U_ECALL;
+            }
         }
     }
 
@@ -688,7 +694,36 @@ void riscv_cpu_do_interrupt(CPUState *cs)
     if (env->priv <= PRV_S &&
             cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
         /* handle the trap in S-mode */
-        target_ulong s = env->mstatus;
+        if (riscv_has_ext(env, RVH)) {
+            target_ulong hdeleg = async ? env->hideleg : env->hedeleg;
+
+            if (riscv_cpu_virt_enabled(env) && ((hdeleg >> cause) & 1) &&
+                !force_hs_execp) {
+                /* Trap to VS mode */
+            } else if (riscv_cpu_virt_enabled(env)) {
+                /* Trap into HS mode, from virt */
+                riscv_cpu_swap_hypervisor_regs(env);
+                env->hstatus = set_field(env->hstatus, HSTATUS_SP2V,
+                                         get_field(env->hstatus, HSTATUS_SPV));
+                env->hstatus = set_field(env->hstatus, HSTATUS_SP2P,
+                                         get_field(env->mstatus, SSTATUS_SPP));
+                env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
+                                         riscv_cpu_virt_enabled(env));
+
+                riscv_cpu_set_virt_enabled(env, 0);
+                riscv_cpu_set_force_hs_excep(env, 0);
+            } else {
+                /* Trap into HS mode */
+                env->hstatus = set_field(env->hstatus, HSTATUS_SP2V,
+                                         get_field(env->hstatus, HSTATUS_SPV));
+                env->hstatus = set_field(env->hstatus, HSTATUS_SP2P,
+                                         get_field(env->mstatus, SSTATUS_SPP));
+                env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
+                                         riscv_cpu_virt_enabled(env));
+            }
+        }
+
+        s = env->mstatus;
         s = set_field(s, MSTATUS_SPIE, env->priv_ver >= PRIV_VERSION_1_10_0 ?
             get_field(s, MSTATUS_SIE) : get_field(s, MSTATUS_UIE << env->priv));
         s = set_field(s, MSTATUS_SPP, env->priv);
@@ -702,7 +737,21 @@ void riscv_cpu_do_interrupt(CPUState *cs)
         riscv_cpu_set_mode(env, PRV_S);
     } else {
         /* handle the trap in M-mode */
-        target_ulong s = env->mstatus;
+        if (riscv_has_ext(env, RVH)) {
+            if (riscv_cpu_virt_enabled(env)) {
+                riscv_cpu_swap_hypervisor_regs(env);
+            }
+            env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
+                                      riscv_cpu_virt_enabled(env));
+            env->mstatus = set_field(env->mstatus, MSTATUS_MTL,
+                                      riscv_cpu_force_hs_excep_enabled(env));
+
+            /* Trapping to M mode, virt is disabled */
+            riscv_cpu_set_virt_enabled(env, 0);
+            riscv_cpu_set_force_hs_excep(env, 0);
+        }
+
+        s = env->mstatus;
         s = set_field(s, MSTATUS_MPIE, env->priv_ver >= PRIV_VERSION_1_10_0 ?
             get_field(s, MSTATUS_MIE) : get_field(s, MSTATUS_UIE << env->priv));
         s = set_field(s, MSTATUS_MPP, env->priv);
-- 
2.25.0

[PATCH v2 22/35] target/riscv: Add Hypervisor trap return support

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
---
 target/riscv/op_helper.c | 62 +++++++++++++++++++++++++++++++++-------
 1 file changed, 52 insertions(+), 10 deletions(-)

diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index 455eb28907..804936e9d5 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -73,6 +73,8 @@ target_ulong helper_csrrc(CPURISCVState *env, target_ulong src,
 
 target_ulong helper_sret(CPURISCVState *env, target_ulong cpu_pc_deb)
 {
+    target_ulong prev_priv, prev_virt, mstatus;
+
     if (!(env->priv >= PRV_S)) {
         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
     }
@@ -87,16 +89,46 @@ target_ulong helper_sret(CPURISCVState *env, target_ulong cpu_pc_deb)
         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
     }
 
-    target_ulong mstatus = env->mstatus;
-    target_ulong prev_priv = get_field(mstatus, MSTATUS_SPP);
-    mstatus = set_field(mstatus,
-        env->priv_ver >= PRIV_VERSION_1_10_0 ?
-        MSTATUS_SIE : MSTATUS_UIE << prev_priv,
-        get_field(mstatus, MSTATUS_SPIE));
-    mstatus = set_field(mstatus, MSTATUS_SPIE, 1);
-    mstatus = set_field(mstatus, MSTATUS_SPP, PRV_U);
+    mstatus = env->mstatus;
+
+    if (riscv_has_ext(env, RVH) && !riscv_cpu_virt_enabled(env)) {
+        /* We support Hypervisor extensions and virtulisation is disabled */
+        target_ulong hstatus = env->hstatus;
+
+        prev_priv = get_field(mstatus, MSTATUS_SPP);
+        prev_virt = get_field(hstatus, HSTATUS_SPV);
+
+        hstatus = set_field(hstatus, HSTATUS_SPV,
+                                 get_field(hstatus, HSTATUS_SP2V));
+        mstatus = set_field(mstatus, MSTATUS_SPP,
+                            get_field(hstatus, HSTATUS_SP2P));
+        hstatus = set_field(hstatus, HSTATUS_SP2V, 0);
+        hstatus = set_field(hstatus, HSTATUS_SP2P, 0);
+        mstatus = set_field(mstatus, SSTATUS_SIE,
+                            get_field(mstatus, SSTATUS_SPIE));
+        mstatus = set_field(mstatus, SSTATUS_SPIE, 1);
+
+        env->mstatus = mstatus;
+        env->hstatus = hstatus;
+
+        if (prev_virt) {
+            riscv_cpu_swap_hypervisor_regs(env);
+        }
+
+        riscv_cpu_set_virt_enabled(env, prev_virt);
+    } else {
+        prev_priv = get_field(mstatus, MSTATUS_SPP);
+
+        mstatus = set_field(mstatus,
+            env->priv_ver >= PRIV_VERSION_1_10_0 ?
+            MSTATUS_SIE : MSTATUS_UIE << prev_priv,
+            get_field(mstatus, MSTATUS_SPIE));
+        mstatus = set_field(mstatus, MSTATUS_SPIE, 1);
+        mstatus = set_field(mstatus, MSTATUS_SPP, PRV_U);
+        env->mstatus = mstatus;
+    }
+
     riscv_cpu_set_mode(env, prev_priv);
-    env->mstatus = mstatus;
 
     return retpc;
 }
@@ -114,14 +146,24 @@ target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb)
 
     target_ulong mstatus = env->mstatus;
     target_ulong prev_priv = get_field(mstatus, MSTATUS_MPP);
+    target_ulong prev_virt = get_field(mstatus, MSTATUS_MPV);
     mstatus = set_field(mstatus,
         env->priv_ver >= PRIV_VERSION_1_10_0 ?
         MSTATUS_MIE : MSTATUS_UIE << prev_priv,
         get_field(mstatus, MSTATUS_MPIE));
     mstatus = set_field(mstatus, MSTATUS_MPIE, 1);
     mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
-    riscv_cpu_set_mode(env, prev_priv);
+    mstatus = set_field(mstatus, MSTATUS_MPV, 0);
     env->mstatus = mstatus;
+    riscv_cpu_set_mode(env, prev_priv);
+
+    if (riscv_has_ext(env, RVH)) {
+        if (prev_virt) {
+            riscv_cpu_swap_hypervisor_regs(env);
+        }
+
+        riscv_cpu_set_virt_enabled(env, prev_virt);
+    }
 
     return retpc;
 }
-- 
2.25.0

[PATCH v2 23/35] target/riscv: Add hfence instructions

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
---
 target/riscv/insn32.decode                    | 23 ++++++-----
 .../riscv/insn_trans/trans_privileged.inc.c   | 40 +++++++++++++++++++
 2 files changed, 54 insertions(+), 9 deletions(-)

diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index 77f794ed70..cfd9ca6d2b 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -63,20 +63,25 @@
 @r2_rm   .......   ..... ..... ... ..... ....... %rs1 %rm %rd
 @r2      .......   ..... ..... ... ..... ....... %rs1 %rd
 
+@hfence_gvma ....... ..... .....   ... ..... ....... %rs2 %rs1
+@hfence_bvma ....... ..... .....   ... ..... ....... %rs2 %rs1
+
 @sfence_vma ....... ..... .....   ... ..... ....... %rs2 %rs1
 @sfence_vm  ....... ..... .....   ... ..... ....... %rs1
 
 
 # *** Privileged Instructions ***
-ecall      000000000000     00000 000 00000 1110011
-ebreak     000000000001     00000 000 00000 1110011
-uret       0000000    00010 00000 000 00000 1110011
-sret       0001000    00010 00000 000 00000 1110011
-hret       0010000    00010 00000 000 00000 1110011
-mret       0011000    00010 00000 000 00000 1110011
-wfi        0001000    00101 00000 000 00000 1110011
-sfence_vma 0001001    ..... ..... 000 00000 1110011 @sfence_vma
-sfence_vm  0001000    00100 ..... 000 00000 1110011 @sfence_vm
+ecall       000000000000     00000 000 00000 1110011
+ebreak      000000000001     00000 000 00000 1110011
+uret        0000000    00010 00000 000 00000 1110011
+sret        0001000    00010 00000 000 00000 1110011
+hret        0010000    00010 00000 000 00000 1110011
+mret        0011000    00010 00000 000 00000 1110011
+wfi         0001000    00101 00000 000 00000 1110011
+hfence_gvma 0110001    ..... ..... 000 00000 1110011 @hfence_gvma
+hfence_bvma 0010001    ..... ..... 000 00000 1110011 @hfence_bvma
+sfence_vma  0001001    ..... ..... 000 00000 1110011 @sfence_vma
+sfence_vm   0001000    00100 ..... 000 00000 1110011 @sfence_vm
 
 # *** RV32I Base Instruction Set ***
 lui      ....................       ..... 0110111 @u
diff --git a/target/riscv/insn_trans/trans_privileged.inc.c b/target/riscv/insn_trans/trans_privileged.inc.c
index c5e4b3e49a..b9b5a89b52 100644
--- a/target/riscv/insn_trans/trans_privileged.inc.c
+++ b/target/riscv/insn_trans/trans_privileged.inc.c
@@ -108,3 +108,43 @@ static bool trans_sfence_vm(DisasContext *ctx, arg_sfence_vm *a)
 #endif
     return false;
 }
+
+static bool trans_hfence_gvma(DisasContext *ctx, arg_sfence_vma *a)
+{
+#ifndef CONFIG_USER_ONLY
+    if (ctx->priv_ver >= PRIV_VERSION_1_10_0 &&
+        has_ext(ctx, RVH)) {
+        /* Hpervisor extensions exist */
+        /*
+         * if (env->priv == PRV_M ||
+         *   (env->priv == PRV_S &&
+         *    !riscv_cpu_virt_enabled(env) &&
+         *    get_field(ctx->mstatus_fs, MSTATUS_TVM))) {
+         */
+            gen_helper_tlb_flush(cpu_env);
+            return true;
+        /* } */
+    }
+#endif
+    return false;
+}
+
+static bool trans_hfence_bvma(DisasContext *ctx, arg_sfence_vma *a)
+{
+#ifndef CONFIG_USER_ONLY
+    if (ctx->priv_ver >= PRIV_VERSION_1_10_0 &&
+        has_ext(ctx, RVH)) {
+        /* Hpervisor extensions exist */
+        /*
+         * if (env->priv == PRV_M ||
+         *   (env->priv == PRV_S &&
+         *    !riscv_cpu_virt_enabled(env) &&
+         *    get_field(ctx->mstatus_fs, MSTATUS_TVM))) {
+         */
+            gen_helper_tlb_flush(cpu_env);
+            return true;
+        /* } */
+    }
+#endif
+    return false;
+}
-- 
2.25.0

[PATCH v2 24/35] target/riscv: Remove the hret instruction

[Alistair Francis]

The hret instruction does not exist in the new spec versions, so remove
it from QEMU.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/insn32.decode                     | 1 -
 target/riscv/insn_trans/trans_privileged.inc.c | 5 -----
 2 files changed, 6 deletions(-)

diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index cfd9ca6d2b..b883672e63 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -75,7 +75,6 @@ ecall       000000000000     00000 000 00000 1110011
 ebreak      000000000001     00000 000 00000 1110011
 uret        0000000    00010 00000 000 00000 1110011
 sret        0001000    00010 00000 000 00000 1110011
-hret        0010000    00010 00000 000 00000 1110011
 mret        0011000    00010 00000 000 00000 1110011
 wfi         0001000    00101 00000 000 00000 1110011
 hfence_gvma 0110001    ..... ..... 000 00000 1110011 @hfence_gvma
diff --git a/target/riscv/insn_trans/trans_privileged.inc.c b/target/riscv/insn_trans/trans_privileged.inc.c
index b9b5a89b52..76c2fad71c 100644
--- a/target/riscv/insn_trans/trans_privileged.inc.c
+++ b/target/riscv/insn_trans/trans_privileged.inc.c
@@ -58,11 +58,6 @@ static bool trans_sret(DisasContext *ctx, arg_sret *a)
 #endif
 }
 
-static bool trans_hret(DisasContext *ctx, arg_hret *a)
-{
-    return false;
-}
-
 static bool trans_mret(DisasContext *ctx, arg_mret *a)
 {
 #ifndef CONFIG_USER_ONLY
-- 
2.25.0

[PATCH v2 25/35] target/riscv: Only set TB flags with FP status if enabled

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 5b889a0065..aa04e5cca7 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -332,7 +332,10 @@ static inline void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
 #ifdef CONFIG_USER_ONLY
     *flags = TB_FLAGS_MSTATUS_FS;
 #else
-    *flags = cpu_mmu_index(env, 0) | (env->mstatus & MSTATUS_FS);
+    *flags = cpu_mmu_index(env, 0);
+    if (riscv_cpu_fp_enabled(env)) {
+        *flags |= env->mstatus & MSTATUS_FS;
+    }
 #endif
 }
 
-- 
2.25.0

[PATCH v2 26/35] target/riscv: Disable guest FP support based on virtual status

[Alistair Francis]

When the Hypervisor extension is in use we only enable floating point
support when both status and vsstatus have enabled floating point
support.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu_helper.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index e7728cb0ca..827a38324c 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -99,6 +99,9 @@ bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
 bool riscv_cpu_fp_enabled(CPURISCVState *env)
 {
     if (env->mstatus & MSTATUS_FS) {
+        if (riscv_cpu_virt_enabled(env) && !(env->mstatus_hs & MSTATUS_FS)) {
+            return false;
+        }
         return true;
     }
 
-- 
2.25.0

[PATCH v2 27/35] target/riscv: Mark both sstatus and msstatus_hs as dirty

[Alistair Francis]

Mark both sstatus and vsstatus as dirty (3).

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/translate.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index afa2d6eea2..61fe9f03be 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -44,6 +44,7 @@ typedef struct DisasContext {
     /* pc_succ_insn points to the instruction following base.pc_next */
     target_ulong pc_succ_insn;
     target_ulong priv_ver;
+    bool virt_enabled;
     uint32_t opcode;
     uint32_t mstatus_fs;
     uint32_t misa;
@@ -396,6 +397,12 @@ static void mark_fs_dirty(DisasContext *ctx)
     tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
     tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS | MSTATUS_SD);
     tcg_gen_st_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
+
+    if (ctx->virt_enabled) {
+        tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
+        tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS | MSTATUS_SD);
+        tcg_gen_st_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
+    }
     tcg_temp_free(tmp);
 }
 #else
@@ -740,6 +747,11 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     ctx->mem_idx = ctx->base.tb->flags & TB_FLAGS_MMU_MASK;
     ctx->mstatus_fs = ctx->base.tb->flags & TB_FLAGS_MSTATUS_FS;
     ctx->priv_ver = env->priv_ver;
+#if !defined(CONFIG_USER_ONLY)
+    ctx->virt_enabled = riscv_cpu_virt_enabled(env);
+#else
+    ctx->virt_enabled = false;
+#endif
     ctx->misa = env->misa;
     ctx->frm = -1;  /* unknown rounding mode */
     ctx->ext_ifencei = cpu->cfg.ext_ifencei;
-- 
2.25.0

[PATCH v2 28/35] target/riscv: Respect MPRV and SPRV for floating point ops

[Alistair Francis]

mark_fs_dirty() is the only place in translate.c that uses the
virt_enabled bool. Let's respect the contents of MSTATUS.MPRV and
HSTATUS.SPRV when setting the bool as this is used for performing
floating point operations when V=0.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/translate.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 61fe9f03be..240fd7c971 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -748,7 +748,21 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     ctx->mstatus_fs = ctx->base.tb->flags & TB_FLAGS_MSTATUS_FS;
     ctx->priv_ver = env->priv_ver;
 #if !defined(CONFIG_USER_ONLY)
-    ctx->virt_enabled = riscv_cpu_virt_enabled(env);
+    if (riscv_has_ext(env, RVH)) {
+        ctx->virt_enabled = riscv_cpu_virt_enabled(env);
+        if (env->priv_ver == PRV_M &&
+            get_field(env->mstatus, MSTATUS_MPRV) &&
+            get_field(env->mstatus, MSTATUS_MPV)) {
+            ctx->virt_enabled = true;
+        } else if (env->priv == PRV_S &&
+                   !riscv_cpu_virt_enabled(env) &&
+                   get_field(env->hstatus, HSTATUS_SPRV) &&
+                   get_field(env->hstatus, HSTATUS_SPV)) {
+            ctx->virt_enabled = true;
+        }
+    } else {
+        ctx->virt_enabled = false;
+    }
 #else
     ctx->virt_enabled = false;
 #endif
-- 
2.25.0

[PATCH v2 29/35] target/riscv: Allow specifying MMU stage

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu_helper.c | 37 ++++++++++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 9 deletions(-)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 827a38324c..cd2d9341b9 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -277,10 +277,19 @@ void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
  *
  * Adapted from Spike's mmu_t::translate and mmu_t::walk
  *
+ * @env: CPURISCVState
+ * @physical: This will be set to the calculated physical address
+ * @prot: The returned protection attributes
+ * @addr: The virtual address to be translated
+ * @access_type: The type of MMU access
+ * @mmu_idx: Indicates current privilege level
+ * @first_stage: Are we in first stage translation?
+ *               Second stage is used for hypervisor guest translation
  */
 static int get_physical_address(CPURISCVState *env, hwaddr *physical,
                                 int *prot, target_ulong addr,
-                                int access_type, int mmu_idx)
+                                int access_type, int mmu_idx,
+                                bool first_stage)
 {
     /* NOTE: the env->pc value visible here will not be
      * correct, but the value visible to the exception handler
@@ -483,13 +492,21 @@ restart:
 }
 
 static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
-                                MMUAccessType access_type, bool pmp_violation)
+                                MMUAccessType access_type, bool pmp_violation,
+                                bool first_stage)
 {
     CPUState *cs = env_cpu(env);
-    int page_fault_exceptions =
-        (env->priv_ver >= PRIV_VERSION_1_10_0) &&
-        get_field(env->satp, SATP_MODE) != VM_1_10_MBARE &&
-        !pmp_violation;
+    int page_fault_exceptions;
+    if (first_stage) {
+        page_fault_exceptions =
+            (env->priv_ver >= PRIV_VERSION_1_10_0) &&
+            get_field(env->satp, SATP_MODE) != VM_1_10_MBARE &&
+            !pmp_violation;
+    } else {
+        page_fault_exceptions =
+            get_field(env->hgatp, HGATP_MODE) != VM_1_10_MBARE &&
+            !pmp_violation;
+    }
     switch (access_type) {
     case MMU_INST_FETCH:
         cs->exception_index = page_fault_exceptions ?
@@ -516,7 +533,8 @@ hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
     int prot;
     int mmu_idx = cpu_mmu_index(&cpu->env, false);
 
-    if (get_physical_address(&cpu->env, &phys_addr, &prot, addr, 0, mmu_idx)) {
+    if (get_physical_address(&cpu->env, &phys_addr, &prot, addr, 0, mmu_idx,
+                             true)) {
         return -1;
     }
     return phys_addr;
@@ -581,7 +599,8 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
     qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
                   __func__, address, access_type, mmu_idx);
 
-    ret = get_physical_address(env, &pa, &prot, address, access_type, mmu_idx);
+    ret = get_physical_address(env, &pa, &prot, address, access_type, mmu_idx,
+                               true);
 
     if (mode == PRV_M && access_type != MMU_INST_FETCH) {
         if (get_field(env->mstatus, MSTATUS_MPRV)) {
@@ -608,7 +627,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
     } else if (probe) {
         return false;
     } else {
-        raise_mmu_exception(env, address, access_type, pmp_violation);
+        raise_mmu_exception(env, address, access_type, pmp_violation, true);
         riscv_raise_exception(env, cs->exception_index, retaddr);
     }
 #else
-- 
2.25.0

[PATCH v2 30/35] target/riscv: Implement second stage MMU

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu.h        |   1 +
 target/riscv/cpu_helper.c | 193 ++++++++++++++++++++++++++++++++++----
 2 files changed, 175 insertions(+), 19 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index aa04e5cca7..a8534fdf2b 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -104,6 +104,7 @@ struct CPURISCVState {
     target_ulong frm;
 
     target_ulong badaddr;
+    target_ulong guest_phys_fault_addr;
 
     target_ulong priv_ver;
     target_ulong misa;
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index cd2d9341b9..5f96631637 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -285,11 +285,12 @@ void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv)
  * @mmu_idx: Indicates current privilege level
  * @first_stage: Are we in first stage translation?
  *               Second stage is used for hypervisor guest translation
+ * @two_stage: Are we going to perform two stage translation
  */
 static int get_physical_address(CPURISCVState *env, hwaddr *physical,
                                 int *prot, target_ulong addr,
                                 int access_type, int mmu_idx,
-                                bool first_stage)
+                                bool first_stage, bool two_stage)
 {
     /* NOTE: the env->pc value visible here will not be
      * correct, but the value visible to the exception handler
@@ -297,13 +298,40 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
     MemTxResult res;
     MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
     int mode = mmu_idx;
+    bool use_background = false;
 
+    /*
+     * Check if we should use the background registers for the two
+     * stage translation. We don't need to check if we actually need
+     * two stage translation as that happened before this function
+     * was called. Background registers will be used if the guest has
+     * forced a two stage translation to be on (in HS or M mode).
+     */
     if (mode == PRV_M && access_type != MMU_INST_FETCH) {
         if (get_field(env->mstatus, MSTATUS_MPRV)) {
             mode = get_field(env->mstatus, MSTATUS_MPP);
+
+            if (riscv_has_ext(env, RVH) &&
+                get_field(env->mstatus, MSTATUS_MPV)) {
+                use_background = true;
+            }
+        }
+    }
+
+    if (mode == PRV_S && access_type != MMU_INST_FETCH &&
+        riscv_has_ext(env, RVH) && !riscv_cpu_virt_enabled(env)) {
+        if (get_field(env->hstatus, HSTATUS_SPRV)) {
+            mode = get_field(env->mstatus, SSTATUS_SPP);
+            use_background = true;
         }
     }
 
+    if (first_stage == false) {
+        /* We are in stage 2 translation, this is similar to stage 1. */
+        /* Stage 2 is always taken as U-mode */
+        mode = PRV_U;
+    }
+
     if (mode == PRV_M || !riscv_feature(env, RISCV_FEATURE_MMU)) {
         *physical = addr;
         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
@@ -313,13 +341,30 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
     *prot = 0;
 
     hwaddr base;
-    int levels, ptidxbits, ptesize, vm, sum;
-    int mxr = get_field(env->mstatus, MSTATUS_MXR);
+    int levels, ptidxbits, ptesize, vm, sum, mxr, widened;
+
+    if (first_stage == true) {
+        mxr = get_field(env->mstatus, MSTATUS_MXR);
+    } else {
+        mxr = get_field(env->vsstatus, MSTATUS_MXR);
+    }
 
     if (env->priv_ver >= PRIV_VERSION_1_10_0) {
-        base = (hwaddr)get_field(env->satp, SATP_PPN) << PGSHIFT;
+        if (first_stage == true) {
+            if (use_background) {
+                base = (hwaddr)get_field(env->vsatp, SATP_PPN) << PGSHIFT;
+                vm = get_field(env->vsatp, SATP_MODE);
+            } else {
+                base = (hwaddr)get_field(env->satp, SATP_PPN) << PGSHIFT;
+                vm = get_field(env->satp, SATP_MODE);
+            }
+            widened = 0;
+        } else {
+            base = (hwaddr)get_field(env->hgatp, HGATP_PPN) << PGSHIFT;
+            vm = get_field(env->hgatp, HGATP_MODE);
+            widened = 2;
+        }
         sum = get_field(env->mstatus, MSTATUS_SUM);
-        vm = get_field(env->satp, SATP_MODE);
         switch (vm) {
         case VM_1_10_SV32:
           levels = 2; ptidxbits = 10; ptesize = 4; break;
@@ -337,6 +382,7 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
           g_assert_not_reached();
         }
     } else {
+        widened = 0;
         base = (hwaddr)(env->sptbr) << PGSHIFT;
         sum = !get_field(env->mstatus, MSTATUS_PUM);
         vm = get_field(env->mstatus, MSTATUS_VM);
@@ -357,9 +403,16 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
     }
 
     CPUState *cs = env_cpu(env);
-    int va_bits = PGSHIFT + levels * ptidxbits;
-    target_ulong mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
-    target_ulong masked_msbs = (addr >> (va_bits - 1)) & mask;
+    int va_bits = PGSHIFT + levels * ptidxbits + widened;
+    target_ulong mask, masked_msbs;
+
+    if (TARGET_LONG_BITS > (va_bits - 1)) {
+        mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
+    } else {
+        mask = 0;
+    }
+    masked_msbs = (addr >> (va_bits - 1)) & mask;
+
     if (masked_msbs != 0 && masked_msbs != mask) {
         return TRANSLATE_FAIL;
     }
@@ -371,11 +424,29 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
 restart:
 #endif
     for (i = 0; i < levels; i++, ptshift -= ptidxbits) {
-        target_ulong idx = (addr >> (PGSHIFT + ptshift)) &
+        target_ulong idx;
+        if (i == 0) {
+            idx = (addr >> (PGSHIFT + ptshift)) &
+                           ((1 << (ptidxbits + widened)) - 1);
+        } else {
+            idx = (addr >> (PGSHIFT + ptshift)) &
                            ((1 << ptidxbits) - 1);
+        }
 
         /* check that physical address of PTE is legal */
-        hwaddr pte_addr = base + idx * ptesize;
+        hwaddr pte_addr;
+
+        if (two_stage && first_stage) {
+            hwaddr vbase;
+
+            /* Do the second stage translation on the base PTE address. */
+            get_physical_address(env, &vbase, prot, base, access_type,
+                                 mmu_idx, false, true);
+
+            pte_addr = vbase + idx * ptesize;
+        } else {
+            pte_addr = base + idx * ptesize;
+        }
 
         if (riscv_feature(env, RISCV_FEATURE_PMP) &&
             !pmp_hart_has_privs(env, pte_addr, sizeof(target_ulong),
@@ -472,7 +543,12 @@ restart:
             /* for superpage mappings, make a fake leaf PTE for the TLB's
                benefit. */
             target_ulong vpn = addr >> PGSHIFT;
-            *physical = (ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT;
+            if (i == 0) {
+                *physical = (ppn | (vpn & ((1L << (ptshift + widened)) - 1))) <<
+                             PGSHIFT;
+            } else {
+                *physical = (ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT;
+            }
 
             /* set permissions on the TLB entry */
             if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
@@ -529,14 +605,23 @@ static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
 {
     RISCVCPU *cpu = RISCV_CPU(cs);
+    CPURISCVState *env = &cpu->env;
     hwaddr phys_addr;
     int prot;
     int mmu_idx = cpu_mmu_index(&cpu->env, false);
 
-    if (get_physical_address(&cpu->env, &phys_addr, &prot, addr, 0, mmu_idx,
-                             true)) {
+    if (get_physical_address(env, &phys_addr, &prot, addr, 0, mmu_idx,
+                             true, riscv_cpu_virt_enabled(env))) {
         return -1;
     }
+
+    if (riscv_cpu_virt_enabled(env)) {
+        if (get_physical_address(env, &phys_addr, &prot, phys_addr,
+                                 0, mmu_idx, false, true)) {
+            return -1;
+        }
+    }
+
     return phys_addr;
 }
 
@@ -590,17 +675,37 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
     RISCVCPU *cpu = RISCV_CPU(cs);
     CPURISCVState *env = &cpu->env;
 #ifndef CONFIG_USER_ONLY
+    vaddr im_address;
     hwaddr pa = 0;
     int prot;
     bool pmp_violation = false;
+    bool m_mode_two_stage = false;
+    bool hs_mode_two_stage = false;
+    bool first_stage_error = true;
     int ret = TRANSLATE_FAIL;
     int mode = mmu_idx;
 
+    env->guest_phys_fault_addr = 0;
+
     qemu_log_mask(CPU_LOG_MMU, "%s ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
                   __func__, address, access_type, mmu_idx);
 
-    ret = get_physical_address(env, &pa, &prot, address, access_type, mmu_idx,
-                               true);
+    /*
+     * Determine if we are in M mode and MPRV is set or in HS mode and SPRV is
+     * set and we want to access a virtulisation address.
+     */
+    if (riscv_has_ext(env, RVH)) {
+        m_mode_two_stage = env->priv == PRV_M &&
+                           access_type != MMU_INST_FETCH &&
+                           get_field(env->mstatus, MSTATUS_MPRV) &&
+                           get_field(env->mstatus, MSTATUS_MPV);
+
+        hs_mode_two_stage = env->priv == PRV_S &&
+                            !riscv_cpu_virt_enabled(env) &&
+                            access_type != MMU_INST_FETCH &&
+                            get_field(env->hstatus, HSTATUS_SPRV) &&
+                            get_field(env->hstatus, HSTATUS_SPV);
+    }
 
     if (mode == PRV_M && access_type != MMU_INST_FETCH) {
         if (get_field(env->mstatus, MSTATUS_MPRV)) {
@@ -608,9 +713,55 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
         }
     }
 
-    qemu_log_mask(CPU_LOG_MMU,
-                  "%s address=%" VADDR_PRIx " ret %d physical " TARGET_FMT_plx
-                  " prot %d\n", __func__, address, ret, pa, prot);
+    if (riscv_cpu_virt_enabled(env) || m_mode_two_stage || hs_mode_two_stage) {
+        /* Two stage lookup */
+        ret = get_physical_address(env, &pa, &prot, address, access_type,
+                                   mmu_idx, true, true);
+
+        qemu_log_mask(CPU_LOG_MMU,
+                      "%s 1st-stage address=%" VADDR_PRIx " ret %d physical "
+                      TARGET_FMT_plx " prot %d\n",
+                      __func__, address, ret, pa, prot);
+
+        if (ret != TRANSLATE_FAIL) {
+            /* Second stage lookup */
+            im_address = pa;
+
+            ret = get_physical_address(env, &pa, &prot, im_address,
+                                       access_type, mmu_idx, false, true);
+
+            qemu_log_mask(CPU_LOG_MMU,
+                    "%s 2nd-stage address=%" VADDR_PRIx " ret %d physical "
+                    TARGET_FMT_plx " prot %d\n",
+                    __func__, im_address, ret, pa, prot);
+
+            if (riscv_feature(env, RISCV_FEATURE_PMP) &&
+                (ret == TRANSLATE_SUCCESS) &&
+                !pmp_hart_has_privs(env, pa, size, 1 << access_type, mode)) {
+                ret = TRANSLATE_PMP_FAIL;
+            }
+
+            if (ret != TRANSLATE_SUCCESS) {
+                /*
+                 * Guest physical address translation failed, this is a HS
+                 * level exception
+                 */
+                first_stage_error = false;
+                env->guest_phys_fault_addr = (im_address |
+                                              (address &
+                                               (TARGET_PAGE_SIZE - 1))) >> 2;
+            }
+        }
+    } else {
+        /* Single stage lookup */
+        ret = get_physical_address(env, &pa, &prot, address, access_type,
+                                   mmu_idx, true, false);
+
+        qemu_log_mask(CPU_LOG_MMU,
+                      "%s address=%" VADDR_PRIx " ret %d physical "
+                      TARGET_FMT_plx " prot %d\n",
+                      __func__, address, ret, pa, prot);
+    }
 
     if (riscv_feature(env, RISCV_FEATURE_PMP) &&
         (ret == TRANSLATE_SUCCESS) &&
@@ -620,6 +771,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
     if (ret == TRANSLATE_PMP_FAIL) {
         pmp_violation = true;
     }
+
     if (ret == TRANSLATE_SUCCESS) {
         tlb_set_page(cs, address & TARGET_PAGE_MASK, pa & TARGET_PAGE_MASK,
                      prot, mmu_idx, TARGET_PAGE_SIZE);
@@ -627,9 +779,12 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
     } else if (probe) {
         return false;
     } else {
-        raise_mmu_exception(env, address, access_type, pmp_violation, true);
+        raise_mmu_exception(env, address, access_type, pmp_violation, first_stage_error);
         riscv_raise_exception(env, cs->exception_index, retaddr);
     }
+
+    return true;
+
 #else
     switch (access_type) {
     case MMU_INST_FETCH:
-- 
2.25.0

[PATCH v2 31/35] target/riscv: Raise the new execptions when 2nd stage translation fails

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu_helper.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 5f96631637..da994aba57 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -585,16 +585,28 @@ static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
     }
     switch (access_type) {
     case MMU_INST_FETCH:
-        cs->exception_index = page_fault_exceptions ?
-            RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
+        if (riscv_cpu_virt_enabled(env) && !first_stage) {
+            cs->exception_index = RISCV_EXCP_INST_GUEST_PAGE_FAULT;
+        } else {
+            cs->exception_index = page_fault_exceptions ?
+                RISCV_EXCP_INST_PAGE_FAULT : RISCV_EXCP_INST_ACCESS_FAULT;
+        }
         break;
     case MMU_DATA_LOAD:
-        cs->exception_index = page_fault_exceptions ?
-            RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
+        if (riscv_cpu_virt_enabled(env) && !first_stage) {
+            cs->exception_index = RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT;
+        } else {
+            cs->exception_index = page_fault_exceptions ?
+                RISCV_EXCP_LOAD_PAGE_FAULT : RISCV_EXCP_LOAD_ACCESS_FAULT;
+        }
         break;
     case MMU_DATA_STORE:
-        cs->exception_index = page_fault_exceptions ?
-            RISCV_EXCP_STORE_PAGE_FAULT : RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
+        if (riscv_cpu_virt_enabled(env) && !first_stage) {
+            cs->exception_index = RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT;
+        } else {
+            cs->exception_index = page_fault_exceptions ?
+                RISCV_EXCP_STORE_PAGE_FAULT : RISCV_EXCP_STORE_AMO_ACCESS_FAULT;
+        }
         break;
     default:
         g_assert_not_reached();
-- 
2.25.0

[PATCH v2 32/35] target/riscv: Set htval and mtval2 on execptions

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu_helper.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index da994aba57..10786a077b 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -838,6 +838,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
     target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK;
     target_ulong deleg = async ? env->mideleg : env->medeleg;
     target_ulong tval = 0;
+    target_ulong htval = 0;
+    target_ulong mtval2 = 0;
 
     if (!async) {
         /* set tval to badaddr for traps with address information */
@@ -899,6 +901,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
                 env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
                                          riscv_cpu_virt_enabled(env));
 
+                htval = env->guest_phys_fault_addr;
+
                 riscv_cpu_set_virt_enabled(env, 0);
                 riscv_cpu_set_force_hs_excep(env, 0);
             } else {
@@ -909,6 +913,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
                                          get_field(env->mstatus, SSTATUS_SPP));
                 env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
                                          riscv_cpu_virt_enabled(env));
+
+                htval = env->guest_phys_fault_addr;
             }
         }
 
@@ -921,6 +927,7 @@ void riscv_cpu_do_interrupt(CPUState *cs)
         env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
         env->sepc = env->pc;
         env->sbadaddr = tval;
+        env->htval = htval;
         env->pc = (env->stvec >> 2 << 2) +
             ((async && (env->stvec & 3) == 1) ? cause * 4 : 0);
         riscv_cpu_set_mode(env, PRV_S);
@@ -935,6 +942,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
             env->mstatus = set_field(env->mstatus, MSTATUS_MTL,
                                       riscv_cpu_force_hs_excep_enabled(env));
 
+            mtval2 = env->guest_phys_fault_addr;
+
             /* Trapping to M mode, virt is disabled */
             riscv_cpu_set_virt_enabled(env, 0);
             riscv_cpu_set_force_hs_excep(env, 0);
@@ -949,6 +958,7 @@ void riscv_cpu_do_interrupt(CPUState *cs)
         env->mcause = cause | ~(((target_ulong)-1) >> async);
         env->mepc = env->pc;
         env->mbadaddr = tval;
+        env->mtval2 = mtval2;
         env->pc = (env->mtvec >> 2 << 2) +
             ((async && (env->mtvec & 3) == 1) ? cause * 4 : 0);
         riscv_cpu_set_mode(env, PRV_M);
-- 
2.25.0

[PATCH v2 33/35] target/riscv: Add support for the 32-bit MSTATUSH CSR

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.c        |  3 +++
 target/riscv/cpu.h        | 10 ++++++++++
 target/riscv/cpu_bits.h   |  3 +++
 target/riscv/cpu_helper.c | 17 +++++++++++++++++
 target/riscv/csr.c        | 25 +++++++++++++++++++++++++
 target/riscv/op_helper.c  |  4 ++++
 6 files changed, 62 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 44ad768a84..b27066f6a7 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -237,6 +237,9 @@ static void riscv_cpu_dump_state(CPUState *cs, FILE *f, int flags)
 #ifndef CONFIG_USER_ONLY
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mhartid ", env->mhartid);
     qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ", env->mstatus);
+#ifdef TARGET_RISCV32
+    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatush ", env->mstatush);
+#endif
     if (riscv_has_ext(env, RVH)) {
         qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "hstatus ", env->hstatus);
         qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "vsstatus ", env->vsstatus);
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index a8534fdf2b..6f9c29322a 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -127,6 +127,10 @@ struct CPURISCVState {
 
     target_ulong mip;
 
+#ifdef TARGET_RISCV32
+    target_ulong mstatush;
+#endif
+
     uint32_t miclaim;
 
     target_ulong mie;
@@ -164,6 +168,9 @@ struct CPURISCVState {
     target_ulong vscause;
     target_ulong vstval;
     target_ulong vsatp;
+#ifdef TARGET_RISCV32
+    target_ulong vsstatush;
+#endif
 
     target_ulong mtval2;
     target_ulong mtinst;
@@ -176,6 +183,9 @@ struct CPURISCVState {
     target_ulong stval_hs;
     target_ulong satp_hs;
     target_ulong mstatus_hs;
+#ifdef TARGET_RISCV32
+    target_ulong mstatush_hs;
+#endif
 
     target_ulong scounteren;
     target_ulong mcounteren;
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index a24654d137..049032f2ae 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -135,6 +135,9 @@
 #define CSR_MTVEC           0x305
 #define CSR_MCOUNTEREN      0x306
 
+/* 32-bit only */
+#define CSR_MSTATUSH        0x310
+
 /* Legacy Counter Setup (priv v1.9.1) */
 /* Update to #define CSR_MCOUNTINHIBIT 0x320 for 1.11.0 */
 #define CSR_MUCOUNTEREN     0x320
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 10786a077b..e04545adf7 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -126,6 +126,11 @@ void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
         env->mstatus &= ~mstatus_mask;
         env->mstatus |= env->mstatus_hs;
 
+#if defined(TARGET_RISCV32)
+        env->vsstatush = env->mstatush;
+        env->mstatush |= env->mstatush_hs;
+#endif
+
         env->vstvec = env->stvec;
         env->stvec = env->stvec_hs;
 
@@ -149,6 +154,11 @@ void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
         env->mstatus &= ~mstatus_mask;
         env->mstatus |= env->vsstatus;
 
+#if defined(TARGET_RISCV32)
+        env->mstatush_hs = env->mstatush;
+        env->mstatush |= env->vsstatush;
+#endif
+
         env->stvec_hs = env->stvec;
         env->stvec = env->vstvec;
 
@@ -937,10 +947,17 @@ void riscv_cpu_do_interrupt(CPUState *cs)
             if (riscv_cpu_virt_enabled(env)) {
                 riscv_cpu_swap_hypervisor_regs(env);
             }
+#ifdef TARGET_RISCV32
+            env->mstatush = set_field(env->mstatush, MSTATUS_MPV,
+                                       riscv_cpu_virt_enabled(env));
+            env->mstatush = set_field(env->mstatush, MSTATUS_MTL,
+                                       riscv_cpu_force_hs_excep_enabled(env));
+#else
             env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
                                       riscv_cpu_virt_enabled(env));
             env->mstatus = set_field(env->mstatus, MSTATUS_MTL,
                                       riscv_cpu_force_hs_excep_enabled(env));
+#endif
 
             mtval2 = env->guest_phys_fault_addr;
 
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 2e6700bbeb..572a478e8c 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -371,6 +371,27 @@ static int write_mstatus(CPURISCVState *env, int csrno, target_ulong val)
     return 0;
 }
 
+#ifdef TARGET_RISCV32
+static int read_mstatush(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->mstatush;
+    return 0;
+}
+
+static int write_mstatush(CPURISCVState *env, int csrno, target_ulong val)
+{
+    if ((val ^ env->mstatush) & (MSTATUS_MPV)) {
+        tlb_flush(env_cpu(env));
+    }
+
+    val &= MSTATUS_MPV | MSTATUS_MTL;
+
+    env->mstatush = val;
+
+    return 0;
+}
+#endif
+
 static int read_misa(CPURISCVState *env, int csrno, target_ulong *val)
 {
     *val = env->misa;
@@ -1214,6 +1235,10 @@ static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_MTVEC] =               { any,  read_mtvec,       write_mtvec       },
     [CSR_MCOUNTEREN] =          { any,  read_mcounteren,  write_mcounteren  },
 
+#if defined(TARGET_RISCV32)
+    [CSR_MSTATUSH] =            { any,  read_mstatush,    write_mstatush    },
+#endif
+
     /* Legacy Counter Setup (priv v1.9.1) */
     [CSR_MUCOUNTEREN] =         { any,  read_mucounteren, write_mucounteren },
     [CSR_MSCOUNTEREN] =         { any,  read_mscounteren, write_mscounteren },
diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index 804936e9d5..dca68fa96e 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -153,7 +153,11 @@ target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb)
         get_field(mstatus, MSTATUS_MPIE));
     mstatus = set_field(mstatus, MSTATUS_MPIE, 1);
     mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
+#ifdef TARGET_RISCV32
+    env->mstatush = set_field(env->mstatush, MSTATUS_MPV, 0);
+#else
     mstatus = set_field(mstatus, MSTATUS_MPV, 0);
+#endif
     env->mstatus = mstatus;
     riscv_cpu_set_mode(env, prev_priv);
 
-- 
2.25.0

[PATCH v2 34/35] target/riscv: Add the MSTATUS_MPV_ISSET helper macro

[Alistair Francis]

Add a helper macro MSTATUS_MPV_ISSET() which will determine if the
MSTATUS_MPV bit is set for both 32-bit and 64-bit RISC-V.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 target/riscv/cpu_bits.h   | 11 +++++++++++
 target/riscv/cpu_helper.c |  4 ++--
 target/riscv/op_helper.c  |  2 +-
 target/riscv/translate.c  |  2 +-
 4 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 049032f2ae..7f64ee1174 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -363,8 +363,19 @@
 #define MSTATUS_TVM         0x00100000 /* since: priv-1.10 */
 #define MSTATUS_TW          0x20000000 /* since: priv-1.10 */
 #define MSTATUS_TSR         0x40000000 /* since: priv-1.10 */
+#if defined(TARGET_RISCV64)
 #define MSTATUS_MTL         0x4000000000ULL
 #define MSTATUS_MPV         0x8000000000ULL
+#elif defined(TARGET_RISCV32)
+#define MSTATUS_MTL         0x00000040
+#define MSTATUS_MPV         0x00000080
+#endif
+
+#ifdef TARGET_RISCV32
+# define MSTATUS_MPV_ISSET(env)  get_field(env->mstatush, MSTATUS_MPV)
+#else
+# define MSTATUS_MPV_ISSET(env)  get_field(env->mstatus, MSTATUS_MPV)
+#endif
 
 #define MSTATUS64_UXL       0x0000000300000000ULL
 #define MSTATUS64_SXL       0x0000000C00000000ULL
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index e04545adf7..b9e90dfd9a 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -322,7 +322,7 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
             mode = get_field(env->mstatus, MSTATUS_MPP);
 
             if (riscv_has_ext(env, RVH) &&
-                get_field(env->mstatus, MSTATUS_MPV)) {
+                MSTATUS_MPV_ISSET(env)) {
                 use_background = true;
             }
         }
@@ -720,7 +720,7 @@ bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
         m_mode_two_stage = env->priv == PRV_M &&
                            access_type != MMU_INST_FETCH &&
                            get_field(env->mstatus, MSTATUS_MPRV) &&
-                           get_field(env->mstatus, MSTATUS_MPV);
+                           MSTATUS_MPV_ISSET(env);
 
         hs_mode_two_stage = env->priv == PRV_S &&
                             !riscv_cpu_virt_enabled(env) &&
diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index dca68fa96e..8736f689c2 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -146,7 +146,7 @@ target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb)
 
     target_ulong mstatus = env->mstatus;
     target_ulong prev_priv = get_field(mstatus, MSTATUS_MPP);
-    target_ulong prev_virt = get_field(mstatus, MSTATUS_MPV);
+    target_ulong prev_virt = MSTATUS_MPV_ISSET(env);
     mstatus = set_field(mstatus,
         env->priv_ver >= PRIV_VERSION_1_10_0 ?
         MSTATUS_MIE : MSTATUS_UIE << prev_priv,
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 240fd7c971..ae8818efb3 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -752,7 +752,7 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
         ctx->virt_enabled = riscv_cpu_virt_enabled(env);
         if (env->priv_ver == PRV_M &&
             get_field(env->mstatus, MSTATUS_MPRV) &&
-            get_field(env->mstatus, MSTATUS_MPV)) {
+            MSTATUS_MPV_ISSET(env)) {
             ctx->virt_enabled = true;
         } else if (env->priv == PRV_S &&
                    !riscv_cpu_virt_enabled(env) &&
-- 
2.25.0

[PATCH v2 35/35] target/riscv: Allow enabling the Hypervisor extension

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
---
 target/riscv/cpu.c | 5 +++++
 target/riscv/cpu.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index b27066f6a7..c47d10b739 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -453,6 +453,9 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         if (cpu->cfg.ext_u) {
             target_misa |= RVU;
         }
+        if (cpu->cfg.ext_h) {
+            target_misa |= RVH;
+        }
 
         set_misa(env, RVXLEN | target_misa);
     }
@@ -488,6 +491,8 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("c", RISCVCPU, cfg.ext_c, true),
     DEFINE_PROP_BOOL("s", RISCVCPU, cfg.ext_s, true),
     DEFINE_PROP_BOOL("u", RISCVCPU, cfg.ext_u, true),
+    /* This is experimental so mark with 'x-' */
+    DEFINE_PROP_BOOL("x-h", RISCVCPU, cfg.ext_h, false),
     DEFINE_PROP_BOOL("Counters", RISCVCPU, cfg.ext_counters, true),
     DEFINE_PROP_BOOL("Zifencei", RISCVCPU, cfg.ext_ifencei, true),
     DEFINE_PROP_BOOL("Zicsr", RISCVCPU, cfg.ext_icsr, true),
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 6f9c29322a..d52f209361 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -258,6 +258,7 @@ typedef struct RISCVCPU {
         bool ext_c;
         bool ext_s;
         bool ext_u;
+        bool ext_h;
         bool ext_counters;
         bool ext_ifencei;
         bool ext_icsr;
-- 
2.25.0

Re: [PATCH v2 00/35] Add RISC-V Hypervisor Extension v0.5

[Palmer Dabbelt]

On Fri, 31 Jan 2020 17:01:35 PST (-0800), Alistair Francis wrote:
> This patch series adds the RISC-V Hypervisor extension v0.5. This is the
> latest draft spec of the Hypervisor extension.
>
> The Hypervisor extension is disabled by default, so this series should
> result in no changes to anyone using QEMU unless they enable the
> extension. The extention can be enabled with the -cpu property (see
> below).
>
> Testing of this implementation has been done by using the baremetal
> Xvisor Hypervisor. We are able to run two Linux guests (that's all I
> have tried) as guests in 64-bit. In 32-bit so far I can only run
> baremetal guests, but I think this is a baremetal boot loader issue and
> not an issue in QEMU.
>
> The RISC-V KVM implementation was also written using these patches. The
> KVM implementation is currently under review.
>
> At the moment this spec is in a draft state and is subject to change. As
> QEMU is extreamly useful in early bring up I think it makes sense for
> QEMU to support non-frozen extensions.
>
> Thanks to Anup for doing the initial port of Xvisor. The port is avaliable here:
> https://github.com/avpatel/xvisor-next and will run on QEMU.
>
> Also thanks to Atish for implementing the SBI call support in Xvisor and
> for lots of help debugging.
>
> To run this yourself:
>  1. Apply this patch series to QEMU. The latest branch can be found here:
>       https://github.com/alistair23/qemu/tree/mainline/alistair/riscv-hyp-ext-v0.5.next
>  2. Get the version of OpenSBI that supports the H extension. This can
>     be found here:
>       https://github.com/avpatel/opensbi/tree/riscv_hyp_ext_0_5_v1
>  3. Build the next release of Xvisor. It is available here:
>       https://github.com/avpatel/xvisor-next
>  4. Make sure you build the Xvisor tests, see here for details:
>       https://github.com/avpatel/xvisor-next/tree/master/tests/riscv/virt64/linux
>  5. Run QEMU:
>      ./riscv64-softmmu/qemu-system-riscv64 -nographic \
>        -machine virt -cpu rv64,x-h=true \
>        -serial mon:stdio -serial null -m 4G \
>        -device loader,file=vmm.bin,addr=0x80200000 \
>        -kernel fw_jump.elf \
>        -initrd vmm-disk-linux.img \
>        -append "vmm.console=uart@10000000 vmm.bootcmd=\"vfs mount initrd /;vfs run /boot.xscript;vfs cat /system/banner.txt\""
>
>    Once you get to the prompt you can start the geust by running:
>      guest kick guest0
>    You can then bind to the serial port using:
>      vserial bind guest0/uart0
>    Then you can start Linux using:
>      autoexec
>
>  This was all tested with the mainline 5.2/5.3 kernels.
>
> There is very early work on a Xen port as well which is avaliable here:
> https://github.com/alistair23/xen/tree/alistair/riscv-port
>
> ToDo/Issues
>  - Get 32-bit fully working
>
> v2:
>  - Don't use riscv_cpu_set_force_hs_excep() for 2nd stage MMU fauls as
>    the v0.5 spec has a specific fault
>  - Address review comments
>  - Rebase on master
>  - Remove pointers for mstatus
>
> Alistair Francis (35):
>   target/riscv: Convert MIP CSR to target_ulong
>   target/riscv: Add the Hypervisor extension
>   target/riscv: Add the Hypervisor CSRs to CPUState
>   target/riscv: Add support for the new execption numbers
>   target/riscv: Rename the H irqs to VS irqs
>   target/riscv: Add the virtulisation mode
>   target/riscv: Add the force HS exception mode
>   target/riscv: Fix CSR perm checking for HS mode
>   target/riscv: Print priv and virt in disas log
>   target/riscv: Dump Hypervisor registers if enabled
>   target/riscv: Add Hypervisor CSR access functions
>   target/riscv: Add Hypervisor virtual CSRs accesses
>   target/riscv: Add Hypervisor machine CSRs accesses
>   target/riscv: Add virtual register swapping function
>   target/riscv: Set VS bits in mideleg for Hyp extension
>   target/riscv: Extend the MIE CSR to support virtulisation
>   target/riscv: Extend the SIP CSR to support virtulisation
>   target/riscv: Add support for virtual interrupt setting
>   target/ricsv: Flush the TLB on virtulisation mode changes
>   target/riscv: Generate illegal instruction on WFI when V=1
>   target/riscv: Add hypvervisor trap support
>   target/riscv: Add Hypervisor trap return support
>   target/riscv: Add hfence instructions
>   target/riscv: Remove the hret instruction
>   target/riscv: Only set TB flags with FP status if enabled
>   target/riscv: Disable guest FP support based on virtual status
>   target/riscv: Mark both sstatus and msstatus_hs as dirty
>   target/riscv: Respect MPRV and SPRV for floating point ops
>   target/riscv: Allow specifying MMU stage
>   target/riscv: Implement second stage MMU
>   target/riscv: Raise the new execptions when 2nd stage translation
>     fails
>   target/riscv: Set htval and mtval2 on execptions
>   target/riscv: Add support for the 32-bit MSTATUSH CSR
>   target/riscv: Add the MSTATUS_MPV_ISSET helper macro
>   target/riscv: Allow enabling the Hypervisor extension
>
>  target/riscv/cpu.c                            |  57 ++-
>  target/riscv/cpu.h                            |  58 ++-
>  target/riscv/cpu_bits.h                       | 111 ++--
>  target/riscv/cpu_helper.c                     | 481 ++++++++++++++++--
>  target/riscv/csr.c                            | 369 +++++++++++++-
>  target/riscv/gdbstub.c                        |  11 +-
>  target/riscv/insn32.decode                    |  22 +-
>  .../riscv/insn_trans/trans_privileged.inc.c   |  45 +-
>  target/riscv/op_helper.c                      |  71 ++-
>  target/riscv/translate.c                      |  34 ++
>  10 files changed, 1130 insertions(+), 129 deletions(-)

Thanks.  I'm going to send out the current queue, just to make sure it doesn't
get blocked, and then dig through all this.  It should be essentially ready to
go, IIRC there were just a few patches that changed enough to warrant a review.

Re: [PATCH v2 00/35] Add RISC-V Hypervisor Extension v0.5

[Alistair Francis]

On Mon, Feb 10, 2020 at 10:50 AM Palmer Dabbelt
<palmerdabbelt@google.com> wrote:
>
> On Fri, 31 Jan 2020 17:01:35 PST (-0800), Alistair Francis wrote:
> > This patch series adds the RISC-V Hypervisor extension v0.5. This is the
> > latest draft spec of the Hypervisor extension.
> >
> > The Hypervisor extension is disabled by default, so this series should
> > result in no changes to anyone using QEMU unless they enable the
> > extension. The extention can be enabled with the -cpu property (see
> > below).
> >
> > Testing of this implementation has been done by using the baremetal
> > Xvisor Hypervisor. We are able to run two Linux guests (that's all I
> > have tried) as guests in 64-bit. In 32-bit so far I can only run
> > baremetal guests, but I think this is a baremetal boot loader issue and
> > not an issue in QEMU.
> >
> > The RISC-V KVM implementation was also written using these patches. The
> > KVM implementation is currently under review.
> >
> > At the moment this spec is in a draft state and is subject to change. As
> > QEMU is extreamly useful in early bring up I think it makes sense for
> > QEMU to support non-frozen extensions.
> >
> > Thanks to Anup for doing the initial port of Xvisor. The port is avaliable here:
> > https://github.com/avpatel/xvisor-next and will run on QEMU.
> >
> > Also thanks to Atish for implementing the SBI call support in Xvisor and
> > for lots of help debugging.
> >
> > To run this yourself:
> >  1. Apply this patch series to QEMU. The latest branch can be found here:
> >       https://github.com/alistair23/qemu/tree/mainline/alistair/riscv-hyp-ext-v0.5.next
> >  2. Get the version of OpenSBI that supports the H extension. This can
> >     be found here:
> >       https://github.com/avpatel/opensbi/tree/riscv_hyp_ext_0_5_v1
> >  3. Build the next release of Xvisor. It is available here:
> >       https://github.com/avpatel/xvisor-next
> >  4. Make sure you build the Xvisor tests, see here for details:
> >       https://github.com/avpatel/xvisor-next/tree/master/tests/riscv/virt64/linux
> >  5. Run QEMU:
> >      ./riscv64-softmmu/qemu-system-riscv64 -nographic \
> >        -machine virt -cpu rv64,x-h=true \
> >        -serial mon:stdio -serial null -m 4G \
> >        -device loader,file=vmm.bin,addr=0x80200000 \
> >        -kernel fw_jump.elf \
> >        -initrd vmm-disk-linux.img \
> >        -append "vmm.console=uart@10000000 vmm.bootcmd=\"vfs mount initrd /;vfs run /boot.xscript;vfs cat /system/banner.txt\""
> >
> >    Once you get to the prompt you can start the geust by running:
> >      guest kick guest0
> >    You can then bind to the serial port using:
> >      vserial bind guest0/uart0
> >    Then you can start Linux using:
> >      autoexec
> >
> >  This was all tested with the mainline 5.2/5.3 kernels.
> >
> > There is very early work on a Xen port as well which is avaliable here:
> > https://github.com/alistair23/xen/tree/alistair/riscv-port
> >
> > ToDo/Issues
> >  - Get 32-bit fully working
> >
> > v2:
> >  - Don't use riscv_cpu_set_force_hs_excep() for 2nd stage MMU fauls as
> >    the v0.5 spec has a specific fault
> >  - Address review comments
> >  - Rebase on master
> >  - Remove pointers for mstatus
> >
> > Alistair Francis (35):
> >   target/riscv: Convert MIP CSR to target_ulong
> >   target/riscv: Add the Hypervisor extension
> >   target/riscv: Add the Hypervisor CSRs to CPUState
> >   target/riscv: Add support for the new execption numbers
> >   target/riscv: Rename the H irqs to VS irqs
> >   target/riscv: Add the virtulisation mode
> >   target/riscv: Add the force HS exception mode
> >   target/riscv: Fix CSR perm checking for HS mode
> >   target/riscv: Print priv and virt in disas log
> >   target/riscv: Dump Hypervisor registers if enabled
> >   target/riscv: Add Hypervisor CSR access functions
> >   target/riscv: Add Hypervisor virtual CSRs accesses
> >   target/riscv: Add Hypervisor machine CSRs accesses
> >   target/riscv: Add virtual register swapping function
> >   target/riscv: Set VS bits in mideleg for Hyp extension
> >   target/riscv: Extend the MIE CSR to support virtulisation
> >   target/riscv: Extend the SIP CSR to support virtulisation
> >   target/riscv: Add support for virtual interrupt setting
> >   target/ricsv: Flush the TLB on virtulisation mode changes
> >   target/riscv: Generate illegal instruction on WFI when V=1
> >   target/riscv: Add hypvervisor trap support
> >   target/riscv: Add Hypervisor trap return support
> >   target/riscv: Add hfence instructions
> >   target/riscv: Remove the hret instruction
> >   target/riscv: Only set TB flags with FP status if enabled
> >   target/riscv: Disable guest FP support based on virtual status
> >   target/riscv: Mark both sstatus and msstatus_hs as dirty
> >   target/riscv: Respect MPRV and SPRV for floating point ops
> >   target/riscv: Allow specifying MMU stage
> >   target/riscv: Implement second stage MMU
> >   target/riscv: Raise the new execptions when 2nd stage translation
> >     fails
> >   target/riscv: Set htval and mtval2 on execptions
> >   target/riscv: Add support for the 32-bit MSTATUSH CSR
> >   target/riscv: Add the MSTATUS_MPV_ISSET helper macro
> >   target/riscv: Allow enabling the Hypervisor extension
> >
> >  target/riscv/cpu.c                            |  57 ++-
> >  target/riscv/cpu.h                            |  58 ++-
> >  target/riscv/cpu_bits.h                       | 111 ++--
> >  target/riscv/cpu_helper.c                     | 481 ++++++++++++++++--
> >  target/riscv/csr.c                            | 369 +++++++++++++-
> >  target/riscv/gdbstub.c                        |  11 +-
> >  target/riscv/insn32.decode                    |  22 +-
> >  .../riscv/insn_trans/trans_privileged.inc.c   |  45 +-
> >  target/riscv/op_helper.c                      |  71 ++-
> >  target/riscv/translate.c                      |  34 ++
> >  10 files changed, 1130 insertions(+), 129 deletions(-)
>
> Thanks.  I'm going to send out the current queue, just to make sure it doesn't
> get blocked, and then dig through all this.  It should be essentially ready to
> go, IIRC there were just a few patches that changed enough to warrant a review.

Sounds good.

This series should be pretty straight forward to review. It's very
similar to the previous one.

Alistair

Re: [PATCH v2 07/35] target/riscv: Add the force HS exception mode

[Palmer Dabbelt]

On Fri, 31 Jan 2020 17:01:54 PST (-0800), Alistair Francis wrote:
> Add a FORCE_HS_EXCEP mode to the RISC-V virtulisation status. This bit
> specifies if an exeption should be taken to HS mode no matter the
> current delegation status. This is used when an exeption must be taken
> to HS mode, such as when handling interrupts.
>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu.h        |  2 ++
>  target/riscv/cpu_bits.h   |  6 ++++++
>  target/riscv/cpu_helper.c | 18 ++++++++++++++++++
>  3 files changed, 26 insertions(+)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index a9cbd8584e..42720d65f9 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -273,6 +273,8 @@ bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request);
>  bool riscv_cpu_fp_enabled(CPURISCVState *env);
>  bool riscv_cpu_virt_enabled(CPURISCVState *env);
>  void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable);
> +bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env);
> +void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable);
>  int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch);
>  hwaddr riscv_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
>  void  riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> index 2cdb0de4fe..ad6479796c 100644
> --- a/target/riscv/cpu_bits.h
> +++ b/target/riscv/cpu_bits.h
> @@ -432,6 +432,12 @@
>
>  /* Virtulisation Register Fields */
>  #define VIRT_ONOFF          1
> +/* This is used to save state for when we take an exception. If this is set
> + * that means that we want to force a HS level exception (no matter what the
> + * delegation is set to). This will occur for things such as a second level
> + * page table fault.
> + */
> +#define FORCE_HS_EXCEP      2
>
>  /* RV32 satp CSR field masks */
>  #define SATP32_MODE         0x80000000
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 5844e543f3..1e28103500 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -100,6 +100,24 @@ void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable)
>      env->virt = set_field(env->virt, VIRT_ONOFF, enable);
>  }
>
> +bool riscv_cpu_force_hs_excep_enabled(CPURISCVState *env)
> +{
> +    if (!riscv_has_ext(env, RVH)) {
> +        return false;
> +    }
> +
> +    return get_field(env->virt, FORCE_HS_EXCEP);
> +}
> +
> +void riscv_cpu_set_force_hs_excep(CPURISCVState *env, bool enable)
> +{
> +    if (!riscv_has_ext(env, RVH)) {
> +        return;
> +    }
> +
> +    env->virt = set_field(env->virt, FORCE_HS_EXCEP, enable);
> +}
> +
>  int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint32_t interrupts)
>  {
>      CPURISCVState *env = &cpu->env;

Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>

Re: [PATCH v2 21/35] target/riscv: Add hypvervisor trap support

[Palmer Dabbelt]

On Fri, 31 Jan 2020 17:02:30 PST (-0800), Alistair Francis wrote:
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu_helper.c | 69 +++++++++++++++++++++++++++++++++------
>  1 file changed, 59 insertions(+), 10 deletions(-)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 98017df33b..e7728cb0ca 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -639,6 +639,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
>
>      RISCVCPU *cpu = RISCV_CPU(cs);
>      CPURISCVState *env = &cpu->env;
> +    bool force_hs_execp = riscv_cpu_force_hs_excep_enabled(env);
> +    target_ulong s;
>
>      /* cs->exception is 32-bits wide unlike mcause which is XLEN-bits wide
>       * so we mask off the MSB and separate into trap type and cause.
> @@ -648,19 +650,14 @@ void riscv_cpu_do_interrupt(CPUState *cs)
>      target_ulong deleg = async ? env->mideleg : env->medeleg;
>      target_ulong tval = 0;
>
> -    static const int ecall_cause_map[] = {
> -        [PRV_U] = RISCV_EXCP_U_ECALL,
> -        [PRV_S] = RISCV_EXCP_S_ECALL,
> -        [PRV_H] = RISCV_EXCP_VS_ECALL,
> -        [PRV_M] = RISCV_EXCP_M_ECALL
> -    };
> -
>      if (!async) {
>          /* set tval to badaddr for traps with address information */
>          switch (cause) {
>          case RISCV_EXCP_INST_GUEST_PAGE_FAULT:
>          case RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT:
>          case RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT:
> +            force_hs_execp = true;
> +            /* fallthrough */
>          case RISCV_EXCP_INST_ADDR_MIS:
>          case RISCV_EXCP_INST_ACCESS_FAULT:
>          case RISCV_EXCP_LOAD_ADDR_MIS:
> @@ -678,7 +675,16 @@ void riscv_cpu_do_interrupt(CPUState *cs)
>          /* ecall is dispatched as one cause so translate based on mode */
>          if (cause == RISCV_EXCP_U_ECALL) {
>              assert(env->priv <= 3);
> -            cause = ecall_cause_map[env->priv];
> +
> +            if (env->priv == PRV_M) {
> +                cause = RISCV_EXCP_M_ECALL;
> +            } else if (env->priv == PRV_S && riscv_cpu_virt_enabled(env)) {
> +                cause = RISCV_EXCP_VS_ECALL;
> +            } else if (env->priv == PRV_S && !riscv_cpu_virt_enabled(env)) {
> +                cause = RISCV_EXCP_S_ECALL;
> +            } else if (env->priv == PRV_U) {
> +                cause = RISCV_EXCP_U_ECALL;
> +            }
>          }
>      }
>
> @@ -688,7 +694,36 @@ void riscv_cpu_do_interrupt(CPUState *cs)
>      if (env->priv <= PRV_S &&
>              cause < TARGET_LONG_BITS && ((deleg >> cause) & 1)) {
>          /* handle the trap in S-mode */
> -        target_ulong s = env->mstatus;
> +        if (riscv_has_ext(env, RVH)) {
> +            target_ulong hdeleg = async ? env->hideleg : env->hedeleg;
> +
> +            if (riscv_cpu_virt_enabled(env) && ((hdeleg >> cause) & 1) &&
> +                !force_hs_execp) {
> +                /* Trap to VS mode */
> +            } else if (riscv_cpu_virt_enabled(env)) {
> +                /* Trap into HS mode, from virt */
> +                riscv_cpu_swap_hypervisor_regs(env);
> +                env->hstatus = set_field(env->hstatus, HSTATUS_SP2V,
> +                                         get_field(env->hstatus, HSTATUS_SPV));
> +                env->hstatus = set_field(env->hstatus, HSTATUS_SP2P,
> +                                         get_field(env->mstatus, SSTATUS_SPP));
> +                env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
> +                                         riscv_cpu_virt_enabled(env));
> +
> +                riscv_cpu_set_virt_enabled(env, 0);
> +                riscv_cpu_set_force_hs_excep(env, 0);
> +            } else {
> +                /* Trap into HS mode */
> +                env->hstatus = set_field(env->hstatus, HSTATUS_SP2V,
> +                                         get_field(env->hstatus, HSTATUS_SPV));
> +                env->hstatus = set_field(env->hstatus, HSTATUS_SP2P,
> +                                         get_field(env->mstatus, SSTATUS_SPP));
> +                env->hstatus = set_field(env->hstatus, HSTATUS_SPV,
> +                                         riscv_cpu_virt_enabled(env));
> +            }
> +        }
> +
> +        s = env->mstatus;
>          s = set_field(s, MSTATUS_SPIE, env->priv_ver >= PRIV_VERSION_1_10_0 ?
>              get_field(s, MSTATUS_SIE) : get_field(s, MSTATUS_UIE << env->priv));
>          s = set_field(s, MSTATUS_SPP, env->priv);
> @@ -702,7 +737,21 @@ void riscv_cpu_do_interrupt(CPUState *cs)
>          riscv_cpu_set_mode(env, PRV_S);
>      } else {
>          /* handle the trap in M-mode */
> -        target_ulong s = env->mstatus;
> +        if (riscv_has_ext(env, RVH)) {
> +            if (riscv_cpu_virt_enabled(env)) {
> +                riscv_cpu_swap_hypervisor_regs(env);
> +            }
> +            env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
> +                                      riscv_cpu_virt_enabled(env));
> +            env->mstatus = set_field(env->mstatus, MSTATUS_MTL,
> +                                      riscv_cpu_force_hs_excep_enabled(env));
> +
> +            /* Trapping to M mode, virt is disabled */
> +            riscv_cpu_set_virt_enabled(env, 0);
> +            riscv_cpu_set_force_hs_excep(env, 0);
> +        }
> +
> +        s = env->mstatus;
>          s = set_field(s, MSTATUS_MPIE, env->priv_ver >= PRIV_VERSION_1_10_0 ?
>              get_field(s, MSTATUS_MIE) : get_field(s, MSTATUS_UIE << env->priv));
>          s = set_field(s, MSTATUS_MPP, env->priv);

Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>

Re: [PATCH v2 25/35] target/riscv: Only set TB flags with FP status if enabled

[Palmer Dabbelt]

On Fri, 31 Jan 2020 17:02:41 PST (-0800), Alistair Francis wrote:
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu.h | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 5b889a0065..aa04e5cca7 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -332,7 +332,10 @@ static inline void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
>  #ifdef CONFIG_USER_ONLY
>      *flags = TB_FLAGS_MSTATUS_FS;
>  #else
> -    *flags = cpu_mmu_index(env, 0) | (env->mstatus & MSTATUS_FS);
> +    *flags = cpu_mmu_index(env, 0);
> +    if (riscv_cpu_fp_enabled(env)) {
> +        *flags |= env->mstatus & MSTATUS_FS;
> +    }
>  #endif
>  }

Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>

Re: [PATCH v2 26/35] target/riscv: Disable guest FP support based on virtual status

[Palmer Dabbelt]

On Fri, 31 Jan 2020 17:02:44 PST (-0800), Alistair Francis wrote:
> When the Hypervisor extension is in use we only enable floating point
> support when both status and vsstatus have enabled floating point
> support.
>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu_helper.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index e7728cb0ca..827a38324c 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -99,6 +99,9 @@ bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
>  bool riscv_cpu_fp_enabled(CPURISCVState *env)
>  {
>      if (env->mstatus & MSTATUS_FS) {
> +        if (riscv_cpu_virt_enabled(env) && !(env->mstatus_hs & MSTATUS_FS)) {
> +            return false;
> +        }
>          return true;
>      }

Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>

Re: [PATCH v2 27/35] target/riscv: Mark both sstatus and msstatus_hs as dirty

[Palmer Dabbelt]

On Fri, 31 Jan 2020 17:02:46 PST (-0800), Alistair Francis wrote:
> Mark both sstatus and vsstatus as dirty (3).
>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/translate.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/target/riscv/translate.c b/target/riscv/translate.c
> index afa2d6eea2..61fe9f03be 100644
> --- a/target/riscv/translate.c
> +++ b/target/riscv/translate.c
> @@ -44,6 +44,7 @@ typedef struct DisasContext {
>      /* pc_succ_insn points to the instruction following base.pc_next */
>      target_ulong pc_succ_insn;
>      target_ulong priv_ver;
> +    bool virt_enabled;
>      uint32_t opcode;
>      uint32_t mstatus_fs;
>      uint32_t misa;
> @@ -396,6 +397,12 @@ static void mark_fs_dirty(DisasContext *ctx)
>      tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
>      tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS | MSTATUS_SD);
>      tcg_gen_st_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
> +
> +    if (ctx->virt_enabled) {
> +        tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
> +        tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS | MSTATUS_SD);
> +        tcg_gen_st_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
> +    }

I suppose we could #ifdef this, but I don't think it's worth it.

>      tcg_temp_free(tmp);
>  }
>  #else
> @@ -740,6 +747,11 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
>      ctx->mem_idx = ctx->base.tb->flags & TB_FLAGS_MMU_MASK;
>      ctx->mstatus_fs = ctx->base.tb->flags & TB_FLAGS_MSTATUS_FS;
>      ctx->priv_ver = env->priv_ver;
> +#if !defined(CONFIG_USER_ONLY)
> +    ctx->virt_enabled = riscv_cpu_virt_enabled(env);
> +#else
> +    ctx->virt_enabled = false;
> +#endif
>      ctx->misa = env->misa;
>      ctx->frm = -1;  /* unknown rounding mode */
>      ctx->ext_ifencei = cpu->cfg.ext_ifencei;

Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>

Re: [PATCH v2 33/35] target/riscv: Add support for the 32-bit MSTATUSH CSR

[Palmer Dabbelt]

On Fri, 31 Jan 2020 17:03:05 PST (-0800), Alistair Francis wrote:
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu.c        |  3 +++
>  target/riscv/cpu.h        | 10 ++++++++++
>  target/riscv/cpu_bits.h   |  3 +++
>  target/riscv/cpu_helper.c | 17 +++++++++++++++++
>  target/riscv/csr.c        | 25 +++++++++++++++++++++++++
>  target/riscv/op_helper.c  |  4 ++++
>  6 files changed, 62 insertions(+)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 44ad768a84..b27066f6a7 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -237,6 +237,9 @@ static void riscv_cpu_dump_state(CPUState *cs, FILE *f, int flags)
>  #ifndef CONFIG_USER_ONLY
>      qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mhartid ", env->mhartid);
>      qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatus ", env->mstatus);
> +#ifdef TARGET_RISCV32
> +    qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "mstatush ", env->mstatush);
> +#endif
>      if (riscv_has_ext(env, RVH)) {
>          qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "hstatus ", env->hstatus);
>          qemu_fprintf(f, " %s " TARGET_FMT_lx "\n", "vsstatus ", env->vsstatus);
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index a8534fdf2b..6f9c29322a 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -127,6 +127,10 @@ struct CPURISCVState {
>
>      target_ulong mip;
>
> +#ifdef TARGET_RISCV32
> +    target_ulong mstatush;
> +#endif
> +
>      uint32_t miclaim;
>
>      target_ulong mie;
> @@ -164,6 +168,9 @@ struct CPURISCVState {
>      target_ulong vscause;
>      target_ulong vstval;
>      target_ulong vsatp;
> +#ifdef TARGET_RISCV32
> +    target_ulong vsstatush;
> +#endif
>
>      target_ulong mtval2;
>      target_ulong mtinst;
> @@ -176,6 +183,9 @@ struct CPURISCVState {
>      target_ulong stval_hs;
>      target_ulong satp_hs;
>      target_ulong mstatus_hs;
> +#ifdef TARGET_RISCV32
> +    target_ulong mstatush_hs;
> +#endif
>
>      target_ulong scounteren;
>      target_ulong mcounteren;
> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> index a24654d137..049032f2ae 100644
> --- a/target/riscv/cpu_bits.h
> +++ b/target/riscv/cpu_bits.h
> @@ -135,6 +135,9 @@
>  #define CSR_MTVEC           0x305
>  #define CSR_MCOUNTEREN      0x306
>
> +/* 32-bit only */
> +#define CSR_MSTATUSH        0x310
> +
>  /* Legacy Counter Setup (priv v1.9.1) */
>  /* Update to #define CSR_MCOUNTINHIBIT 0x320 for 1.11.0 */
>  #define CSR_MUCOUNTEREN     0x320
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 10786a077b..e04545adf7 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -126,6 +126,11 @@ void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
>          env->mstatus &= ~mstatus_mask;
>          env->mstatus |= env->mstatus_hs;
>
> +#if defined(TARGET_RISCV32)
> +        env->vsstatush = env->mstatush;
> +        env->mstatush |= env->mstatush_hs;
> +#endif
> +
>          env->vstvec = env->stvec;
>          env->stvec = env->stvec_hs;
>
> @@ -149,6 +154,11 @@ void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env)
>          env->mstatus &= ~mstatus_mask;
>          env->mstatus |= env->vsstatus;
>
> +#if defined(TARGET_RISCV32)
> +        env->mstatush_hs = env->mstatush;
> +        env->mstatush |= env->vsstatush;
> +#endif
> +
>          env->stvec_hs = env->stvec;
>          env->stvec = env->vstvec;
>
> @@ -937,10 +947,17 @@ void riscv_cpu_do_interrupt(CPUState *cs)
>              if (riscv_cpu_virt_enabled(env)) {
>                  riscv_cpu_swap_hypervisor_regs(env);
>              }
> +#ifdef TARGET_RISCV32
> +            env->mstatush = set_field(env->mstatush, MSTATUS_MPV,
> +                                       riscv_cpu_virt_enabled(env));
> +            env->mstatush = set_field(env->mstatush, MSTATUS_MTL,
> +                                       riscv_cpu_force_hs_excep_enabled(env));
> +#else
>              env->mstatus = set_field(env->mstatus, MSTATUS_MPV,
>                                        riscv_cpu_virt_enabled(env));
>              env->mstatus = set_field(env->mstatus, MSTATUS_MTL,
>                                        riscv_cpu_force_hs_excep_enabled(env));
> +#endif
>
>              mtval2 = env->guest_phys_fault_addr;
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 2e6700bbeb..572a478e8c 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -371,6 +371,27 @@ static int write_mstatus(CPURISCVState *env, int csrno, target_ulong val)
>      return 0;
>  }
>
> +#ifdef TARGET_RISCV32
> +static int read_mstatush(CPURISCVState *env, int csrno, target_ulong *val)
> +{
> +    *val = env->mstatush;
> +    return 0;
> +}
> +
> +static int write_mstatush(CPURISCVState *env, int csrno, target_ulong val)
> +{
> +    if ((val ^ env->mstatush) & (MSTATUS_MPV)) {
> +        tlb_flush(env_cpu(env));
> +    }
> +
> +    val &= MSTATUS_MPV | MSTATUS_MTL;
> +
> +    env->mstatush = val;
> +
> +    return 0;
> +}
> +#endif
> +
>  static int read_misa(CPURISCVState *env, int csrno, target_ulong *val)
>  {
>      *val = env->misa;
> @@ -1214,6 +1235,10 @@ static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
>      [CSR_MTVEC] =               { any,  read_mtvec,       write_mtvec       },
>      [CSR_MCOUNTEREN] =          { any,  read_mcounteren,  write_mcounteren  },
>
> +#if defined(TARGET_RISCV32)
> +    [CSR_MSTATUSH] =            { any,  read_mstatush,    write_mstatush    },
> +#endif
> +
>      /* Legacy Counter Setup (priv v1.9.1) */
>      [CSR_MUCOUNTEREN] =         { any,  read_mucounteren, write_mucounteren },
>      [CSR_MSCOUNTEREN] =         { any,  read_mscounteren, write_mscounteren },
> diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
> index 804936e9d5..dca68fa96e 100644
> --- a/target/riscv/op_helper.c
> +++ b/target/riscv/op_helper.c
> @@ -153,7 +153,11 @@ target_ulong helper_mret(CPURISCVState *env, target_ulong cpu_pc_deb)
>          get_field(mstatus, MSTATUS_MPIE));
>      mstatus = set_field(mstatus, MSTATUS_MPIE, 1);
>      mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
> +#ifdef TARGET_RISCV32
> +    env->mstatush = set_field(env->mstatush, MSTATUS_MPV, 0);
> +#else
>      mstatus = set_field(mstatus, MSTATUS_MPV, 0);
> +#endif
>      env->mstatus = mstatus;
>      riscv_cpu_set_mode(env, prev_priv);

Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>

Re: [PATCH v2 00/35] Add RISC-V Hypervisor Extension v0.5

[Palmer Dabbelt]

On Fri, 31 Jan 2020 17:01:35 PST (-0800), Alistair Francis wrote:
> This patch series adds the RISC-V Hypervisor extension v0.5. This is the
> latest draft spec of the Hypervisor extension.
>
> The Hypervisor extension is disabled by default, so this series should
> result in no changes to anyone using QEMU unless they enable the
> extension. The extention can be enabled with the -cpu property (see
> below).
>
> Testing of this implementation has been done by using the baremetal
> Xvisor Hypervisor. We are able to run two Linux guests (that's all I
> have tried) as guests in 64-bit. In 32-bit so far I can only run
> baremetal guests, but I think this is a baremetal boot loader issue and
> not an issue in QEMU.
>
> The RISC-V KVM implementation was also written using these patches. The
> KVM implementation is currently under review.
>
> At the moment this spec is in a draft state and is subject to change. As
> QEMU is extreamly useful in early bring up I think it makes sense for
> QEMU to support non-frozen extensions.
>
> Thanks to Anup for doing the initial port of Xvisor. The port is avaliable here:
> https://github.com/avpatel/xvisor-next and will run on QEMU.
>
> Also thanks to Atish for implementing the SBI call support in Xvisor and
> for lots of help debugging.
>
> To run this yourself:
>  1. Apply this patch series to QEMU. The latest branch can be found here:
>       https://github.com/alistair23/qemu/tree/mainline/alistair/riscv-hyp-ext-v0.5.next
>  2. Get the version of OpenSBI that supports the H extension. This can
>     be found here:
>       https://github.com/avpatel/opensbi/tree/riscv_hyp_ext_0_5_v1
>  3. Build the next release of Xvisor. It is available here:
>       https://github.com/avpatel/xvisor-next
>  4. Make sure you build the Xvisor tests, see here for details:
>       https://github.com/avpatel/xvisor-next/tree/master/tests/riscv/virt64/linux
>  5. Run QEMU:
>      ./riscv64-softmmu/qemu-system-riscv64 -nographic \
>        -machine virt -cpu rv64,x-h=true \
>        -serial mon:stdio -serial null -m 4G \
>        -device loader,file=vmm.bin,addr=0x80200000 \
>        -kernel fw_jump.elf \
>        -initrd vmm-disk-linux.img \
>        -append "vmm.console=uart@10000000 vmm.bootcmd=\"vfs mount initrd /;vfs run /boot.xscript;vfs cat /system/banner.txt\""
>
>    Once you get to the prompt you can start the geust by running:
>      guest kick guest0
>    You can then bind to the serial port using:
>      vserial bind guest0/uart0
>    Then you can start Linux using:
>      autoexec
>
>  This was all tested with the mainline 5.2/5.3 kernels.
>
> There is very early work on a Xen port as well which is avaliable here:
> https://github.com/alistair23/xen/tree/alistair/riscv-port
>
> ToDo/Issues
>  - Get 32-bit fully working
>
> v2:
>  - Don't use riscv_cpu_set_force_hs_excep() for 2nd stage MMU fauls as
>    the v0.5 spec has a specific fault
>  - Address review comments
>  - Rebase on master
>  - Remove pointers for mstatus
>
> Alistair Francis (35):
>   target/riscv: Convert MIP CSR to target_ulong
>   target/riscv: Add the Hypervisor extension
>   target/riscv: Add the Hypervisor CSRs to CPUState
>   target/riscv: Add support for the new execption numbers
>   target/riscv: Rename the H irqs to VS irqs
>   target/riscv: Add the virtulisation mode
>   target/riscv: Add the force HS exception mode
>   target/riscv: Fix CSR perm checking for HS mode
>   target/riscv: Print priv and virt in disas log
>   target/riscv: Dump Hypervisor registers if enabled
>   target/riscv: Add Hypervisor CSR access functions
>   target/riscv: Add Hypervisor virtual CSRs accesses
>   target/riscv: Add Hypervisor machine CSRs accesses
>   target/riscv: Add virtual register swapping function
>   target/riscv: Set VS bits in mideleg for Hyp extension
>   target/riscv: Extend the MIE CSR to support virtulisation
>   target/riscv: Extend the SIP CSR to support virtulisation
>   target/riscv: Add support for virtual interrupt setting
>   target/ricsv: Flush the TLB on virtulisation mode changes
>   target/riscv: Generate illegal instruction on WFI when V=1
>   target/riscv: Add hypvervisor trap support
>   target/riscv: Add Hypervisor trap return support
>   target/riscv: Add hfence instructions
>   target/riscv: Remove the hret instruction
>   target/riscv: Only set TB flags with FP status if enabled
>   target/riscv: Disable guest FP support based on virtual status
>   target/riscv: Mark both sstatus and msstatus_hs as dirty
>   target/riscv: Respect MPRV and SPRV for floating point ops
>   target/riscv: Allow specifying MMU stage
>   target/riscv: Implement second stage MMU
>   target/riscv: Raise the new execptions when 2nd stage translation
>     fails
>   target/riscv: Set htval and mtval2 on execptions
>   target/riscv: Add support for the 32-bit MSTATUSH CSR
>   target/riscv: Add the MSTATUS_MPV_ISSET helper macro
>   target/riscv: Allow enabling the Hypervisor extension
>
>  target/riscv/cpu.c                            |  57 ++-
>  target/riscv/cpu.h                            |  58 ++-
>  target/riscv/cpu_bits.h                       | 111 ++--
>  target/riscv/cpu_helper.c                     | 481 ++++++++++++++++--
>  target/riscv/csr.c                            | 369 +++++++++++++-
>  target/riscv/gdbstub.c                        |  11 +-
>  target/riscv/insn32.decode                    |  22 +-
>  .../riscv/insn_trans/trans_privileged.inc.c   |  45 +-
>  target/riscv/op_helper.c                      |  71 ++-
>  target/riscv/translate.c                      |  34 ++
>  10 files changed, 1130 insertions(+), 129 deletions(-)

OK, so everything should be reviewed and on for-master now.  I'll include it as
part of my next PR.

Thanks!

Re: [PATCH v2 00/35] Add RISC-V Hypervisor Extension v0.5

[Alistair Francis]

On Mon, Feb 17, 2020 at 11:11 AM Palmer Dabbelt
<palmerdabbelt@google.com> wrote:
>
> On Fri, 31 Jan 2020 17:01:35 PST (-0800), Alistair Francis wrote:
> > This patch series adds the RISC-V Hypervisor extension v0.5. This is the
> > latest draft spec of the Hypervisor extension.
> >
> > The Hypervisor extension is disabled by default, so this series should
> > result in no changes to anyone using QEMU unless they enable the
> > extension. The extention can be enabled with the -cpu property (see
> > below).
> >
> > Testing of this implementation has been done by using the baremetal
> > Xvisor Hypervisor. We are able to run two Linux guests (that's all I
> > have tried) as guests in 64-bit. In 32-bit so far I can only run
> > baremetal guests, but I think this is a baremetal boot loader issue and
> > not an issue in QEMU.
> >
> > The RISC-V KVM implementation was also written using these patches. The
> > KVM implementation is currently under review.
> >
> > At the moment this spec is in a draft state and is subject to change. As
> > QEMU is extreamly useful in early bring up I think it makes sense for
> > QEMU to support non-frozen extensions.
> >
> > Thanks to Anup for doing the initial port of Xvisor. The port is avaliable here:
> > https://github.com/avpatel/xvisor-next and will run on QEMU.
> >
> > Also thanks to Atish for implementing the SBI call support in Xvisor and
> > for lots of help debugging.
> >
> > To run this yourself:
> >  1. Apply this patch series to QEMU. The latest branch can be found here:
> >       https://github.com/alistair23/qemu/tree/mainline/alistair/riscv-hyp-ext-v0.5.next
> >  2. Get the version of OpenSBI that supports the H extension. This can
> >     be found here:
> >       https://github.com/avpatel/opensbi/tree/riscv_hyp_ext_0_5_v1
> >  3. Build the next release of Xvisor. It is available here:
> >       https://github.com/avpatel/xvisor-next
> >  4. Make sure you build the Xvisor tests, see here for details:
> >       https://github.com/avpatel/xvisor-next/tree/master/tests/riscv/virt64/linux
> >  5. Run QEMU:
> >      ./riscv64-softmmu/qemu-system-riscv64 -nographic \
> >        -machine virt -cpu rv64,x-h=true \
> >        -serial mon:stdio -serial null -m 4G \
> >        -device loader,file=vmm.bin,addr=0x80200000 \
> >        -kernel fw_jump.elf \
> >        -initrd vmm-disk-linux.img \
> >        -append "vmm.console=uart@10000000 vmm.bootcmd=\"vfs mount initrd /;vfs run /boot.xscript;vfs cat /system/banner.txt\""
> >
> >    Once you get to the prompt you can start the geust by running:
> >      guest kick guest0
> >    You can then bind to the serial port using:
> >      vserial bind guest0/uart0
> >    Then you can start Linux using:
> >      autoexec
> >
> >  This was all tested with the mainline 5.2/5.3 kernels.
> >
> > There is very early work on a Xen port as well which is avaliable here:
> > https://github.com/alistair23/xen/tree/alistair/riscv-port
> >
> > ToDo/Issues
> >  - Get 32-bit fully working
> >
> > v2:
> >  - Don't use riscv_cpu_set_force_hs_excep() for 2nd stage MMU fauls as
> >    the v0.5 spec has a specific fault
> >  - Address review comments
> >  - Rebase on master
> >  - Remove pointers for mstatus
> >
> > Alistair Francis (35):
> >   target/riscv: Convert MIP CSR to target_ulong
> >   target/riscv: Add the Hypervisor extension
> >   target/riscv: Add the Hypervisor CSRs to CPUState
> >   target/riscv: Add support for the new execption numbers
> >   target/riscv: Rename the H irqs to VS irqs
> >   target/riscv: Add the virtulisation mode
> >   target/riscv: Add the force HS exception mode
> >   target/riscv: Fix CSR perm checking for HS mode
> >   target/riscv: Print priv and virt in disas log
> >   target/riscv: Dump Hypervisor registers if enabled
> >   target/riscv: Add Hypervisor CSR access functions
> >   target/riscv: Add Hypervisor virtual CSRs accesses
> >   target/riscv: Add Hypervisor machine CSRs accesses
> >   target/riscv: Add virtual register swapping function
> >   target/riscv: Set VS bits in mideleg for Hyp extension
> >   target/riscv: Extend the MIE CSR to support virtulisation
> >   target/riscv: Extend the SIP CSR to support virtulisation
> >   target/riscv: Add support for virtual interrupt setting
> >   target/ricsv: Flush the TLB on virtulisation mode changes
> >   target/riscv: Generate illegal instruction on WFI when V=1
> >   target/riscv: Add hypvervisor trap support
> >   target/riscv: Add Hypervisor trap return support
> >   target/riscv: Add hfence instructions
> >   target/riscv: Remove the hret instruction
> >   target/riscv: Only set TB flags with FP status if enabled
> >   target/riscv: Disable guest FP support based on virtual status
> >   target/riscv: Mark both sstatus and msstatus_hs as dirty
> >   target/riscv: Respect MPRV and SPRV for floating point ops
> >   target/riscv: Allow specifying MMU stage
> >   target/riscv: Implement second stage MMU
> >   target/riscv: Raise the new execptions when 2nd stage translation
> >     fails
> >   target/riscv: Set htval and mtval2 on execptions
> >   target/riscv: Add support for the 32-bit MSTATUSH CSR
> >   target/riscv: Add the MSTATUS_MPV_ISSET helper macro
> >   target/riscv: Allow enabling the Hypervisor extension
> >
> >  target/riscv/cpu.c                            |  57 ++-
> >  target/riscv/cpu.h                            |  58 ++-
> >  target/riscv/cpu_bits.h                       | 111 ++--
> >  target/riscv/cpu_helper.c                     | 481 ++++++++++++++++--
> >  target/riscv/csr.c                            | 369 +++++++++++++-
> >  target/riscv/gdbstub.c                        |  11 +-
> >  target/riscv/insn32.decode                    |  22 +-
> >  .../riscv/insn_trans/trans_privileged.inc.c   |  45 +-
> >  target/riscv/op_helper.c                      |  71 ++-
> >  target/riscv/translate.c                      |  34 ++
> >  10 files changed, 1130 insertions(+), 129 deletions(-)
>
> OK, so everything should be reviewed and on for-master now.  I'll include it as
> part of my next PR.

Woo! Thanks

Alistair

>
> Thanks!